Yep. You just have to use an audio editor to shorten it to 30sec, copy it onto the miniSD card, and use BitPim to add it to the phones list of authorized ringtones. I tried it both ways, and it works flawlessly.

Here are the tutorials I used:

Ringtones to VX8600 miniSD card

Ringtones to VX8600 Internal Memory 1

Ringtones to VX8600 Internal Memory 2