First I interpreted your question the same as John - and had the same answer.

Then I thought you want to sound the alarm only when all char are the same, in which case my solution would be:

?lcString = repl(subs(lcString ,1,1),len(lcString ))

>I need the fastest way to verify for similar characters in a variable. For example, I need to take action when I see a value such as "aaaaaaaa" or "bbbbbbbbbb". What's the best way to accomplish that?