I never tried this before but in this situation I had to, and the best part is it worked flawlessly.
My father-in-law has a Japanese fujitsu Biblio edition laptop, with windows 98se and office 2K installed (both Japanese versions) well his Office 2k only had word, excel, and outlook. My wife's sister needed power point to do a presentation for her job. So I took out my office XP cd, and installed only power point, frontpage express, and access onto this system. I choose to do a custom install and picked the parts I wanted to install, as well as choosing to leave the components already installed from office 2k intact. It works flawlessly, and they are interchangeable!
very nice,
BB