Are you trying to extend C: or F:? or both?  If you are only trying to add space to F:, then it isn't necessary to delete/recreate it after reconfiguring to add the two new drives - even Windows' diskpart can extend the F: drive (it cannot extend C:) into the new unallocated space.  You certainly can delete/recreate, but you don't need to if only extending the data partition.
I have a PERC 4e/Di with 4 300gB drives setup as a single 840gB virtual disk.  The virtual disk is partitioned into C (system) and F (data) drives running Win2003 Std.  I am running out of space.  I purchased 2 additional 300gB drives (exact same models as originals).  I want to expand the virtual drive to include the two new drives and then repartition to increase available storage. I am using OpenManage to access the Perc 4e/Di.  When I open the virtual disk, I can see the original four physical drives.  If I just plug in the new drives, will they appear?  Do they require formatting?  How are they added to the virtual disk?  Once the virtual disk contains the new drives do I use Partition Magic or something similar to expand the existing drives?
PE2800 RAID 5 Storage expansion