I think Wink can attest to this being that he was/is in the recruiting business, but from what I recall, recruiters have a spreasheet that they use to figure out cumulative GPA between more than one college. It basically takes into account the credits you have at your old school (community college), with the credits you have at your current school, weights them properly, and spits out a cumulative GPA.
Also, I wouldn't worry about this too much (unless you have a lot of F bombs at your CC). The GPA in your major seems to matter more than anything else. I.E. If you are studying mathematics, and have all A's and B's in your math classes, but screwed away a history grade, pottery class grade, and an English grade, you'll probably experience some leniency....
Remember folks, if you have any hideous grades, your GPA isn't lost forever. Bad semesters/classes happen to everybody. Many schools have fairly lax 'retake' policies, that will flat out replace your crappy grade with the new one. I'm not saying to piss away your classes now because you can just retake them later, but i'm saying that if you get Satan himself for a tough class and you get a D or even fail it, god forbid, check into retaking it. Bringing an F to an A will work WONDERS for a GPA (not that i've ever failed a class, or even gotten a bad grade

).
End of rant.