As mke_et advised, you just copy the entire project directory that encloses the .mcp file and the rest of the project's files/directories. In addition, after you make the copy, you might want to issue the following commands in the IDE:
1) Project | Reset Project Entry Paths
2) Project | Re-search for Files
These two commands make the CW IDE "forget" the previous file path information used to build the program, and forces it to reconstruct this information by searching the existing directory. I'd then rebuild the project from scratch (Project | Remove Object Code..., Project | Make), to confirm that the IDE was able to sort things out on its own. If you experience problems, then you may have to tinker with the settings in the Access Paths preferences panel.
---Tom