Large Hard Drive on Compaq 4/75 CXL

Hi,
I have a Compaq 4/75 CXL Laptop that has a small hard drive in it. I am trying to upgrade it to a 2.1GB HDD, but the computer will only accept a custom drive of 2931 Cyl. Max. This one is 4,096! How can I do this??? My only idea is some special BIOS or Driver. If you can help me I would greatly appreciate it.