You MUST use the driver for PERC or it will not know how to talk to the controller and it will never see any drives to install to. You need to 1) provide the driver at F6 from floppy, 2) try using the F6/USB utility, or 3) use nlite to integrate the driver.
Is there a reason you keep wanting to fdisk? What is on the "CD with boot files"? Just a DOS boot disk, or like a PE disk? If you want to/must use this utility to fdisk before the install, the ONLY way it will work is if you can feed it the drivers, but without knowing what you are trying to do here, I don't know if there is a way to do it. If it were me, I would simply boot to the nlite-prepped CD and get it installed :)
"I thought I would not hear back from you until Monday"
I don't work for Dell, so I am not restricted (morally or by policy) to my shift or business/working hours :)