How do I extend the C: partion on a raid system in server2003 without losing any data

I have a windows 2003 server with three dirves set up as a raid5 into two partions. The first partion is c: (12 gig) and the rest is D: (data) about 250gig.

My problem is that I need to add more space to c: without making any changes to the second partion - I do not want to do anything that might change, alter, blow away the second partion.
Could I add a drive and use a mount point(?) to extend the size of the C: partion?
This is a Dell Demension ServerStart Free Trial