is it possible to burn a VCD format file onto a DVD-R and view it on a DVD player?

yes, but VCD as you know is 352 x 240 @ 44 khz mpeg 1, best to convert to 352 x 704 @ 48 khz mpeg2 a valid dvd format

unless your dvd player can play SVCD's, then next best format would be 480x480 @ 44 khz mpeg2 ( or upsample the audio to 48 khz and use the ifo trick to fool the DVD player into playing a non spec DVD file, though on some players it will not work )

keep in mind at vcd spec, even though source is divx ( you did not mention resolution ), it will look like a vhs tape in terms of playback quality

NO but convert it to dvd format instead of vcd format and you can quite easily, or if your dvd player plays vcds just burn a vcd. I am guessing you want to put multiple vcds on a dvd and I know of no way to do that. plus vcd is much lower resolution than most xvids and all dvds.

Some DVD players, more so the newer models, can read computer related files such as MP3, Images etc. Those will be read off a CD. A DVD has to be burned through DVD burning software to a DVD disc. (They look the same but they're not) Simply copying the MPEGs without putting them through a DVD burner software and closing the DVD (Finishing) will not work on all players.

VCD format can be played on DVD player just what my DVD player did.

Note: If you copy from VCD to DVD then you won't get better quality because the quality stay the same.

Every DVD R has capability to burn a VCD so you can defiantly do it with NERO or Easy DVD creator