I have a workbook with 12 sheets, a userform and a couple of modules. This
is my first foray into using a UserForm for data entry. I run the UserForm
from a customized ribbon tab. I would like to set the ControlSource property
in a textbox to a sheet called "UserData" into cell B4.
When I try to enter Worksheets("UserData").Range("B4") (or all combinations)
I get an error: "Could not set the ControlSource property. Invalid property
value."

Could you please explain how I do this properly?

Thanks very much.

... rick