Yes, they can be reprogrammed.
When you say "Other System", that raises some questions. These radios are either VHF OR UHF. The "other system" would need to be on the same band, same mode (analog or DMR), etc.
Since you posted this in the Amateur Radio Forum, I've got to ask if you meant you wanted to use it on the amateur radio bands, or are you strictly talking about using this for "work" use?