This works for me to open the VOA hourly news podcast:

Try changing the string to your playlist location and running it right frm the dang .desktop file.

I use qoles FM-Boost and add a preset frequency by tweaking his file...

Then I run Pekka & Juha Rönkkö's FMTX desktop widget v0.5.0 on my desktop with FM-Boost enabled.

So I hit the FMTX button then the Media Player script button and I'm rockin'
My only wish would be for Pekka & Juha to make an actual app button that toggles their FMTX package on and off so I can put it in b0unc3's most excellent Quick Launch and reach it without diving back down to the desktop when I'm using the screen for another app like Sygic or E-mail.

...And speaking about tweakin' files and most excellent efforts... check out thp's Superfly.fm. He's done what you're trying to do with this gem.

BTW, thp and qwerty12 without a doubt, are some of the best resources available...
Just cue up their posts for some good reading one night.

EDIT: I'm also thinkin' you may have to many forward slashes after file:
This file:///home instead of file:////home

EDIT EDIT dude: example attached

Unpack the 2 files and Read Me in the attached zip

Put [yodude.desktop] >> N900:\usr\share\applications\hildon

Put [yodude.png] >> N900:\usr\share\icons\hicolor\64x64

Close up your file manager and now check your apps list and you should now have yodude. It will open Media player to a very good radio station.

Check out the code and adapt it to your needs dude.