Let us make a distinction here.
RAM - we know where this is and how its used
EEPROM - data storage @ 0xB600 or similar address
EPROM - code space generally from 0xC000 to 0xFFFF
There are several serial and parallel programmers which can put code in the EPROM area if there is a quartz window and the part can be erased. Since you are able to load code with hyperterm, I'm guessing that the EPROM contains a boot loader of some type. I'm not sure you can execute code from the EEPROM, but there is probably no way to cause the boot loader to link to that address.
The problem is that the RESET and interrupt vectors are at a location in the EPROM which you cannot change. I think you need to get an erasable part to do what you want to do.