Styg,
Welcome to the ICE Forums. Can you provide a little more detail on the books you own? Date of publication etc.
The Rolemaster Classic (2005 or so, I do not remember the exact date) system is RM2 (1980's) redone back a few years ago and is listed as RMC, where as Rolemaster Standard System (1990's) is RMSS and is very close to RMFRP.
It can make a big difference as to what software if any people recommend.
MDC