What is the error message? A couple things I'd check:
1) make sure that your OnClick() event is set up correctly (to check go to
the design view of your form, select your control, open it's properties to
the event tab, go to the On Click event where it should say 'Event Procedure'
and click the '...' button. If it comes up to your Sub as below, then that
is set up correctly.
2) make sure you've passed your functions the correct number of arguements.
3) if your function requires more that one arguement, it requires that you
assign the value of the function to a variable (and I'm not sure why) as in:
Private Sub cmdExportFile_Click()
dim temp
temp = modExportSoftware(arg1, arg2)
End Sub
Would I be correct in assuming that your function (in your module) compiled
& saved ok? If that doesn't help, I'll need more details.