Can you mail merge into a Word 2003 userform textbox?

Don't know if this is possible, but if it is, any pointers/advice would be appreciated.

I have a Word 2003 userform which contains an address block, comprising several textboxes. What I am considering is:

1. Whilst the userform has focus, somehow using Words mail merge feature (or similar) to select an address from a spreadsheet and add it to the userform. When the userform is in use the spreadsheet will not be open.
   
   
2. If the address is not in the spreadsheet I want to be able to add the address manually and check a box to save the address details to the (unopen) spreadsheet when the userform exits.

Any ideas?

So you want to look up addresses in Excel and populate them in your word userform? Will the spreadsheet be open/visible at all?

The spreadsheet will not be open.

What I was hoping to do is add a command button to the userform which, when clicked, will allow the user to select the address somehow. For example, something like the mail merge feature in Word 2003 which presents a list of the details contained in the spreadsheet without actually opening the spreadsheet - see attached.

Any ideas?

Anybody got any ideas?