Need some DVD burning help!

I'm calling to anyone who can help me!

I have a movie file, .rmvb format, that I'd like to get onto a DVD. Also, I have a .mp4 file that I would like on a DVD.

How would I do this? Would I need to buy converting software or what?

I have PowerProducer 2 Gold, which doesn't recognize either of those types of files. I also have Nero StartSmart, which recognizes .mp4, but it only lets me create VCDs and SVCDs.

Any help would be greatly appreciated! Thank you!

PS: Life is good. Just finished my second year of college!