Oh my bad. I'm sorry I must have misunderstood the post. You want to run a virtual machine of XP, correct? If you can get the VM booted to XP, then from there doing what you need to do shouldn't be a problem.
I must be an idiot, because I'm not fully understanding your post. lol. Sorry. Maybe word it differently?
Okay I guess I'm even more of an idiot. I've had a stressful morning, so excuse me if I am not thinking correctly.
You should be able to boot the VM, then go and download (or install) Dr.DivX onto that VM, and then just transfer the files you want to convert there. Then start the conversion and everything should be fine.
CPU - AMD Phenom X4 9500 2.2 GHZ
Motherboard - MSI MS-7374
Chipset - nVidia nForce 750a Sli
RAM - 6GB PC2-6400
Video Card - NVIDIA GeForce 8800 GTS