If you have the same synths as your friend he should not need to freeze.
Think about this most of the demo songs from CW play back just fine on any system as long as the system is up to it spec wise. They often come as bundle files.
The older ones have both MIDI and audio in them. Some of the newer ones as well.
The other question is if the FX in the project is the same on your system and his. Though Sonar can deal with this by alerting you that a plugin is missing. The project will still play back though.
As to why your Dim Pro is not working using his tracks is a head scratcher. Even if you don't have the right patch the synth should still work. Also I'm not sure why it appears frozen if he didn't freeze it.
What you may want to do is insert a new Dim Pro and output the MIDI track to it. Ask him for the patch he used and you should be good to go.
I would also check which version he has of Dim Pro. As well as know exactly his version of Sonar as well as any patches to it.
I have found that Sonar is remarkable in its ability to open old project files. It has been improved through the years to handle just about all issues.
Keep in mind that bundle files are not played directly. They are uncompressed and a folder is created that holds the project file and a folder for any audio. It is this project that opens into Sonar. Not the bundle file. That remains intact.