Script to allow extended tags to be used in iTunes

[sonicendeavor]

Hi All.
I'm using Media Monkey as my primary software to handle my music, but still use iTunes to manage my iPod. I may eventually switch to have MM handle my iPod, but prefer iTunes at the present time.
I'd like to be able to use the extended tag information (tempo, mood, occasion,custom tags) in the iTunes smart playlists, but obviously iTunes is lacking in the area of tags and has no dedicated place to read or write this metadata.
What I'm thinking is to use a script to populate this information in the comments field in the ID3v2 tag so iTunes can read it.

After update, the comments field would look something like:
Rating=3.5;Tempo=fast;Mood=Upbeat;Occasion=Party;Custom1=iPod

The script would perform the following functions:
1) Open the MP3 file
2) Overwrite the COMM frame with the concatenated tag fields.
3) Set the language descriptor in the COMM frame to "eng" (english), (needed by iTunes to recognize the frame).
4) Update the tag.
5) Move to the next file & loop back to step 1 until all tracks have been updated.

I can probably stumble through writing the code, but if anyone knows of an existing script that does this or something similar, I'd appreciate any information along those lines. I looked through the existing scripts in a post that's tracking MM scripts, and saw one script that does something similar, but it only appeared to update the MM library, not the actual ID3 tag.
Thanks in advance for your help and advice,
Bill