Updown control question
 

Using Excel Excel 11.6 SP1 under Win XP Pro SP2:

I added an MS UpDown control to my form and tried to set a textbox to be its
buddy control, but Excel gave me an error message that said that the buddy
control had to be 'a separate control within the same container' and
wouldn't accept it. The VBA help file for the UpDown states:

The buddy control can be any control that can be linked to the UpDown
control through the BuddyControl property, and usually displays data, such
as a TextBox control or a CommandButton control.

That indicates that a textbox is at least eligible to be a buddy control.
Why won't Excel accept this assignment?

Thanks
William