Disassemble and locate /remote limitation in ARM9 firmware.

I have a .hex file (flash upgrade) for a special device, running an ARM9 CPU The firmware allows user to specify a value, up to 247. The ROM defaults to value of 100, until user enter other value. But no matter what user enter, it checks that the value is not >247. The check for >247 - is what I wish to get rid of. IDA is the tool you'll most likely need to do this job. The language used to make that ROM was C.