[SQL] Sorting users into one group

[eMike]

On my forum, a gamingforum, I have loads of members who registers username syntaxes like "Clan_Nickname" or "Guild_Nickname".

I am in need of sorting this out, for example (and more specifically) getting all users with the "Clan-A_" prefix into usergroup "Clan A" or with the "Guild-B_" prefix nto usergroup "Guild B"

How would I go about doing that? (Except doing it manually)

I do not know much about databases, but im hoping that with the use of some magic SQL command in the SQL Query section of the vB ACP, that this can be done.

Any help would be sooo very appreciated!