You might need to post more information about things like which microprocessor you are using and whether you are expecting to burn the hex file into the microprocessor's flash rom or whether you need to program into extern Eprom.

I'd assume from your question that you are planning to load your program into flash-rom. Usually the the company that makes the microprocess will have some free software for loading it. You can often find it on their homepage. When you post the microprocessor manufacturer here, someone might be able to help you more.

I use Philips brand microprocessors and their flash-rom programming routine is called, "WinIsp" for Windows In-System-Programming. If you are using Dallas Semiconductor brands then your process will be different.

Your program named "Rpchsim" isn't familiar to me. But if you post the brand you're using, others can help.

Good luck with the project,
-Jay C. Box