Welcome to Laptop GPS World.
Microsoft Streets and Trips 2008 has street level coverage for Puerto Rico, but if memory serves me well, the address look-up feature has not been enabled yet.
I just looked at iNav iGuidance 4. It seems you can search for addresses. I tried to find some addresses on the web for testing, but I only came across P.O.BOXs. If you give me some sample addresses I can try to look them up in iGuidance 4.
I could still look at Garmin Mobile PC and DeLorme Street Atlas 2009, but not before tomorrow. This moment I don't have access to the PC where those programs are installed.