Should be very easy to copy the mutli map feature from the Hj to H file. THe new coding will be towards the end of the map file, this will have at the beginning the locations of the call function and in the case of RXN it will be located and referenced in 3 places, match those 3 places on the original to the H file and copy the call function on to the new file. then you will need to change the Bit referencing in the coding later on for the nmot, accel, brake as well as they will be different.

IDA pro is really the only way to do it , you just need a hex editor then to cross reference and make the changes..

get the autoscript to load the file, split the .bin into high and low and half the jobs done.