Forbidden Pattern Policy - simple example

Sometimes simple things are not simple.
So is the forbidden pattern policy from the TFS 2010 Power Tools which actually should give you a warning when you try to check in files according to regular expression.
The configuration of this policy is a little bit to simple, it helps you exactly nothing

Trying regular expression like '.+\.config' and the like do not work.
Searching the internet for solutions I found another guy who was equally frustrated, but also someone who has made it work, only that it is a little long and complex (see there).
Nevertheless thanks a lot to this guy, I was finally able to strip it down to kind of a working minimum.

^(.+\.config$)

Don't ask why it works this way. I don't understand the grouping, I don't understand the $ before the bracket. Anyway, it works.