Thanks guys, for pointing me in the right direction. Once again I learned some new things!

Having to go to Word Options | Customize to turn on the AutoText icon for Commands not displayed in the Ribbon was a good thing to figure out.

After that I created a a simple test macro template and added two Auto Text entries to the Building blocks Gallery.

Then did some rough code like this:

[VBA]Private Sub Document_ContentControlOnExit(ByVal ContentControl As ContentControl, Cancel As Boolean)

If ContentControl.Tag = "choice" Then

Dim choice As String

choice = ActiveDocument.SelectContentControlsByTag("choice").Item(1).Range.Text

ActiveDocument.AttachedTemplate.AutoTextEntries("Terms " & choice).Insert _
Where:=ActiveDocument.Bookmarks("Terms").Range

End If
End Sub[/VBA]

That worked. I'll clean it up for my circumstances.

Any other pointers on how to approach this? Was glad to figure out AutoText, very cool feature to this Word rookie!