I am not very sure how do you mean by "if autocad 2016 VBA is called from a 32 bit Excel VBA in a 64bit system". My guess would be that you have Excel VBA code that automate AutoCAD 2016 (setting reference to AutoCAD 2016 Type library). In this case (assuming your AutoCAD 2016 is 64-bit), there is no "ObjectID32" in AutoCAD COM object model. So, the your code referring "ObjectID" is correct, in theory. However, since your code is actually run in Excel's 32-bit VBA, and "ObjectID" and a 64-bit long integer, which CANNOT live in 32-bit environment, thus, your code will crash at the line where ObjectID is referred. Actually, you do not have to run to crash, in Excel VBA, if you click menu "Debug->Compile [VBA project name]", Excel itself will crash, if the code referring AutoCAD's 64-bit type data, such as ObjectID.
So, you may have to find a workaround, such as not referring ObjectID in your code at all (if the code's business logic can still work, of course); or you have to use 64-bit Excel, or you limit the AutoCAD logic run inside AutoCAD VBA, not in Excel VBA. As matter of fact, automating AutoCAD from outside app, such as Excel is hardly a good solution. Doing it other way around usually a much better, especially when Excel is used (or mis-used) mainly for storing data.