6
ImageSize property on 32 (specifies the size of the control' icons)

Calc1->ImageSize = 32;
Calc1->Font->Size = TVariant(long(16));
Calc1->ButtonWidth = 48;
Calc1->ButtonHeight = 32;
Calc1->EditHeight = 42;
Calc1->Images(TVariant(String("gBJJgBAIDAAEg4AEEKAD/hz/EMNh8TIRNGwAjEZAEXjAojKAjMLjABhkaABAk0plUrlktl0vmExmUzmk1m03nE5nU7nk9miAoE+oVDolFo1HpFJpU5h8Sf9OqFNqUOq") +
"NUqdPq9VrFWrlbr1QpdhAFAkFis1ntFptVrtkrpszrNvmVxqk3uVtm1kmF3sdBvF/wGBmV+j9BYGHwWJulfxdax2NyFdx2JlV6l9Nw7AAGZymdz2Cy2GxErvWcz9ivlw" +
"yV21cuxugwktzGIzmvwtl0+53U5y0a0Wazmmyu/3dCyOMyXHx/J5nIr9q3uyqnBxFN3G46ma4vb7mD2Ng4nZze00fDkHC7t7us2rOX5tguetpHRlmz4HVqnXk1PjHO+C" +
"MPo9MBMC+j2vC8j7wS8cFNI4kBo05UIvfCT/NsnsApU+0Fqg/T+oy/kPxC0sEQfErKQK96+w28UWRI8UGvO8sTLS9r2PWmsMJTDTask3CsIbIEQRA3shOXEEAO/GclJ9" +
"FEKrrA8FRbKMXRIlb0JxCkjS1LMswhCcvuel0cv26cSMa8Ufx+2sQwhEUoSXOCjSbLcnxjKc7sdKUVyq28NtVI71P9P7JxtQEapjQ6fzfM8zPfNE2PhIsLL63E40slk5" +
"y7N89LcyU9SvMb3SdUc6VJLj5VLVLfO/PS9KzNFHUa/0XyBD0dxlS9cxhMlTRSoNXypPErWDPyfNS+MwprRNO0FD8wVVZ1AI08URwVRjtJ1WCn21QkkUrXVLVPQS/XIk" +
"FgTxT9iONZ9xVTdq+L1eKg3kkF6Upe68XtfV51/MtrVjBlwYFL1ev8y1/P6/lyzzYl02wntj0RVFmS1Qa+M5as93QxEUW9e993rfmQ2+vy65M/mL1lhl/2bj2ByVduMt" +
"NhCJT9hdz41nN14Ld12Z9UjfI/oUAaGseiw6+uFLLhcVabJOS5RqOE0BHlZ5VnEr5fOMs3st+aa/bbRzrJGV51Y0b0DbqaWXZD90hIsPbjWu52+6Wyadpe66hhO+P/Xi" +
"oW5rD8ZbrUZuVg6n1dsE/cXmewu1m9PVwnd35/nueXho/NaJzmjc61W76esuT77eG8pTquy9TwWH8LEzG8RDfFalx3Gcfvna9rvG/cptGLd9tuI6TZOP5Fiqi99vea+X" +
"4VRcBq/JZZtVQ9cwSs5lsXE372+a9z7PbfB3VVqHyvMctLto8uob6eV0m/cD6MN2v+T33t6sBut42vdv2bJ8a997x2maFJfK+qArbGJPEKE+1qTflMsIdW/GCJX17KcT" +
"6/czr/X+u1g29B7j/4BQfWkkx4zIHisjhPCmE0K4SwtXM+d4BvHRwNZOoBph9IJvPek9d40FoMJxf691jj2ywQQcHEWET4XJwkTszlVqm2GokewxtBT1DpQjRxDN0rUV" +
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"T8okhqFd4a5yxL0rvulYtKCsZiWxWkc1s1cRoxxwhA31DLE0mR9l9HqX8fJgTDmFMVH0MIsRzVYnwnMi1dyzmhLt2kS2pxIiU62Wj5ptQGlSYFakLonTUJNLKaM5Wzlf" +
"fEkuFkk5wTrhVO2eE7G6lJhxFFYUZ55zmn0WuBCD4pzhirFCKkbomsOoIYmZx5p90LoYWGPdD5g0QmJRKYxbZ6zYoVQ2jVGylSak7KSkFH6RSjpHKFuU+YMyNo5SulkC" +
"6I0vonTCitMXPoEpVS2H5FQfEqp2R1opIgAEkJISYARTCukOhmPNI5Ex/wzGHUsicMwA1LHgQ90Y/KpoQHAD+pB/R4NzIaMAB9Xaw1gqaAOsh/A/ptIkWUfhGK1kZH8R" +
"gH5GqvgArqRmt4AAPrTroRofBGADkqr6Rmu4D7CEaHARiwpJrEEZsXXwlVjyMWRsaRqwdkLGNBABZmytmyMnaINZqyVpLR2ftKAAAdd6h2osbaskdiq4EZtgSmyNcbVW" +
"RJNXe3AA7REar3b0stlAAXBtoRmvJGLjEYAHUWsFcwCD/rnaop9aEICMAPdK5hT6xpeuzdOtAgKuJeGfdq6ggEbkTvAP+p9UCHXrvKkcgIA=="));
Calc1->Caption = L"<img>3</img>";

5
ImageSize property on 16 (default) (specifies the size of the control' icons)

Calc1->ImageSize = 16;
Calc1->Images(TVariant(String("gBJJgBAIDAAEg4AEEKAD/hz/EMNh8TIRNGwAjEZAEXjAojKAjMLjABhkaABAk0plUrlktl0vmExmUzmk1m03nE5nU7nk9miAoE+oVDolFo1HpFJpU5h8Sf9OqFNqUOq") +
"NUqdPq9VrFWrlbr1QpdhAFAkFis1ntFptVrtkrpszrNvmVxqk3uVtm1kmF3sdBvF/wGBmV+j9BYGHwWJulfxdax2NyFdx2JlV6l9Nw7AAGZymdz2Cy2GxErvWcz9ivlw" +
"yV21cuxugwktzGIzmvwtl0+53U5y0a0Wazmmyu/3dCyOMyXHx/J5nIr9q3uyqnBxFN3G46ma4vb7mD2Ng4nZze00fDkHC7t7us2rOX5tguetpHRlmz4HVqnXk1PjHO+C" +
"MPo9MBMC+j2vC8j7wS8cFNI4kBo05UIvfCT/NsnsApU+0Fqg/T+oy/kPxC0sEQfErKQK96+w28UWRI8UGvO8sTLS9r2PWmsMJTDTask3CsIbIEQRA3shOXEEAO/GclJ9" +
"FEKrrA8FRbKMXRIlb0JxCkjS1LMswhCcvuel0cv26cSMa8Ufx+2sQwhEUoSXOCjSbLcnxjKc7sdKUVyq28NtVI71P9P7JxtQEapjQ6fzfM8zPfNE2PhIsLL63E40slk5" +
"y7N89LcyU9SvMb3SdUc6VJLj5VLVLfO/PS9KzNFHUa/0XyBD0dxlS9cxhMlTRSoNXypPErWDPyfNS+MwprRNO0FD8wVVZ1AI08URwVRjtJ1WCn21QkkUrXVLVPQS/XIk" +
"FgTxT9iONZ9xVTdq+L1eKg3kkF6Upe68XtfV51/MtrVjBlwYFL1ev8y1/P6/lyzzYl02wntj0RVFmS1Qa+M5as93QxEUW9e993rfmQ2+vy65M/mL1lhl/2bj2ByVduMt" +
"NhCJT9hdz41nN14Ld12Z9UjfI/oUAaGseiw6+uFLLhcVabJOS5RqOE0BHlZ5VnEr5fOMs3st+aa/bbRzrJGV51Y0b0DbqaWXZD90hIsPbjWu52+6Wyadpe66hhO+P/Xi" +
"oW5rD8ZbrUZuVg6n1dsE/cXmewu1m9PVwnd35/nueXho/NaJzmjc61W76esuT77eG8pTquy9TwWH8LEzG8RDfFalx3Gcfvna9rvG/cptGLd9tuI6TZOP5Fiqi99vea+X" +
"4VRcBq/JZZtVQ9cwSs5lsXE372+a9z7PbfB3VVqHyvMctLto8uob6eV0m/cD6MN2v+T33t6sBut42vdv2bJ8a997x2maFJfK+qArbGJPEKE+1qTflMsIdW/GCJX17KcT" +
"6/czr/X+u1g29B7j/4BQfWkkx4zIHisjhPCmE0K4SwtXM+d4BvHRwNZOoBph9IJvPek9d40FoMJxf691jj2ywQQcHEWET4XJwkTszlVqm2GokewxtBT1DpQjRxDN0rUV" +
"DNKdC3lb6tzNOwh6upMSSYfv4YBCl/bsn9PxiFCEo7SI6Obc9HeOrnY8x4jtHtdpN4GRbaorhsbu18Pph5CiHymI0RpSXGJ/z2oUOxYxG858AyiI+bfJtuTcG5yelBJy" +
"T8okhqFd4a5yxL0rvulYtKCsZiWxWkc1s1cRoxxwhA31DLE0mR9l9HqX8fJgTDmFMVH0MIsRzVYnwnMi1dyzmhLt2kS2pxIiU62Wj5ptQGlSYFakLonTUJNLKaM5Wzlf" +
"fEkuFkk5wTrhVO2eE7G6lJhxFFYUZ55zmn0WuBCD4pzhirFCKkbomsOoIYmZx5p90LoYWGPdD5g0QmJRKYxbZ6zYoVQ2jVGylSak7KSkFH6RSjpHKFuU+YMyNo5SulkC" +
"6I0vonTCitMXPoEpVS2H5FQfEqp2R1opIgAEkJISYARTCukOhmPNI5Ex/wzGHUsicMwA1LHgQ90Y/KpoQHAD+pB/R4NzIaMAB9Xaw1gqaAOsh/A/ptIkWUfhGK1kZH8R" +
"gH5GqvgArqRmt4AAPrTroRofBGADkqr6Rmu4D7CEaHARiwpJrEEZsXXwlVjyMWRsaRqwdkLGNBABZmytmyMnaINZqyVpLR2ftKAAAdd6h2osbaskdiq4EZtgSmyNcbVW" +
"RJNXe3AA7REar3b0stlAAXBtoRmvJGLjEYAHUWsFcwCD/rnaop9aEICMAPdK5hT6xpeuzdOtAgKuJeGfdq6ggEbkTvAP+p9UCHXrvKkcgIA=="));
Calc1->Caption = L"<img>3</img>";

4
How can I change "Cannot divide by zero." (method 2)

Calc1->Template = L"Message(0) = `<b>error:</b> div by zero`";
Calc1->Execute(L"11");
Calc1->Execute(L"/");
Calc1->Execute(L"0");
Calc1->Execute(L"=");

3
How can I change "Cannot divide by zero." (method 1)

Calc1->Message[Excalclib_tlb::MessageEnum::exCannotDivideByZero] = L"<b>error:</b> div by zero";
Calc1->Execute(L"11");
Calc1->Execute(L"/");
Calc1->Execute(L"0");
Calc1->Execute(L"=");

2
How can I enlarge the control's edit area

Calc1->EditHeight = 32;
Calc1->ButtonHeight = 32;
Calc1->ButtonWidth = 32;

1
How can I change the button's appearance

Calc1->set_PictureUp(TVariant(String("gBHJJGHA5MIgAEIe4AAAFhyFiC9fa9bDbbABjEZjUbjkdj0fkEhkUjkklk0nlEplUrlktl0vmExmUzmk1m03nE5nU7nkihgAEL5AgBhj/AAsn8JpRABCZAD/BIcJCwU") +
"DBQYIAIILDIWChYaHAACEh8JCxMTERIVGYyXiIeAfQCPEBDRQMbJRUBCRoaHIaHiJaSiYiSGBjZScBKTMpLRAdNreNioWSgZydBZ7CT8BJUdBAUQ7RoODrJKjkJaaKCj" +
"JSdJQVFJKAAlVq2KjqCIoYinHy9HTkVT1FTYUJiPKeHqaOzjLSTNqDXztDSXNhcAJcdKKZo7GCAb6/QADf6lJS4GDCQAAHcBA"));
Calc1->set_PictureDown(TVariant(String("gBHJJGHA5MIgAEIe4AAAFhyFiDYiQBikVi0XjEZjUbjkdj0fkEhkUjkklk0nlEplUrlktl0vmExmUzmk1m03nEhhgAEL5AgBhj/AAsncJoxABCCAD/BIcJCwUDBQYIA") +
"IgLhICBAQCEBgjHSEDBxcJERYAGRqbjIKKjYiKCwfDxUBByUjISQoKaqUi4eQfZKRFoFLw0fBycrMQQ1KreNgYablv4dQZyfjZWaoaKjEBzSxUZQzczOQJMS4SQraeap" +
"ZiqKavHTNdQSFZLTZcUYmBrreorJSrAoDVBdZa2dpaUhwMYGAgAHcBA=="));
Calc1->ButtonHeight = 24;
Calc1->ButtonWidth = 24;