Update Criteria Data ONLY

Hi all,

I've tried searching the forum, but no luck.

I have a Field say Field1, with data like this:

AB, AC
AB
AC
AB, AD
AA, AB

Where the field contains "AB", I want to replace the data with say "AB - Alpha Beta". But I do not want to change any of the other data. So the outcome should look like:

AB - Alpha Beta, AC
AB - Alpha Beta
AC
AB - Alpha Beta, AD
AA, AB - Alpha Beta

I'd then go on to change AC to say "AC - Alpha Charlie".

All help appreciated,

Jempie