Alex,

Assume the two codes are A and B and the text is "This One" and "That One".

Set up your option group with two buttone, set the button captions to This One and That One. Do not set the controlsource at all. In teh OptionGroup's Refresh method put this;

This.Value = IIF( Alias.Field = "A", 1, 2)

In the InteractiveChange of the OptionGroup put this;

REPLACE Alias.Field WITH IIF(This.Value=1,"A","B") IN Alias