This is going to sound crazy but does anyone have techniques that would allow me to parse boolean logic strings in Sql Server 2005 without extraordinary/rediculous effort?

Here is an example: (SOMEVAR=4 OR SOMEVAR=5) AND (NOT OTHERVAR=Y)

I feel like recursion would help a lot if that were possible in Sql but I'm not really sure how to go about that sort of thing. If not, maybe there's a way to attach an external system to do the recursion for me? Don't worry, I'm not getting my hopes up.