xxMxx,
I created a document for Inter-Tel Tech Support on how to do this several years ago, but it is not a supported practice. The first thing to keep in mind is what codec your system is using for the Voice Processor.
Go to Voice Processor and look for the BS-UVM System Recording Codec value, by default it is G.729A (8kbps) and obviously this is mono since we can't play things back in stereo. So just find an audio converting program that can take the file format that your original recording is done in and convert it to the file format that your system is using.
DO NOT CHANGE THE CODEC THAT YOUR SYSTEM IS USING!!!!! This will cause all kinds of problems for you and the only fix that I will help you with is to change it back to its original codec.
The big thing is to create a recording on the system, it doesn't really have to be anything, but we do need to have one created normally to get the pointers correct and a file name to go with it. Then do a save of that recording number and then swap out the recording with the one you converted. You will need to change the name of the converted recording to the one you are swapping out so that all the pointers stay intact. You do not however need to worry about making sure they are the same size as that doesn't matter from my experience. Next you would load that recording back into the system and test it out.
Thanks,
TE