Hi Acheson,
Thank you for checking my question.
Is the custom iproperty in the drawing?
Yes, the value is in the iproperty of the drawing.
Isolate the Excel portion to check you get the correct value back from the drawing. Try this.
If you get the value then you might have an issue contacting excel. Please attach any error messages your seeing.
MessageBox.Show(iProperties.Value("Custom", "Number"))
That is a good idea. I have tested it and I do get the correct value in the MessageBox.
Also you mentioned parameters. Parameters work differently in the drawing. For text parameters there is no export option to iproperties at least in the older versions. Can you share a screen shot of the value in parameter window or iproperty window your trying to send to excel.
Sure, the value is a number, not a text.

The rule that I want to use to export the value is also in the drawing:
GoExcel.CellValue("MyExcel.xlsm", "Sheet1", "D68") = iProperties.Value("Custom", "VSSPUD_193.7x10x3000")
The Excel sheet is in the same folder as the drawing.
I do not get any errors, just nothing happens.
However, exporting values from assembly works well with the snippet above which makes me wonder if I should use some other snippet in the drawing.
Tom