scratch that idea, winAVI doesn't support divx. but you could always try the bundle available on www.divx.com that includes a converting program that deals with divx files. (available for a reasonable cost).
cuesoft avi to VCD DVD SVCD works like a charm and has a good conversion algarithm to make it convert quickly. you can create a list for it to convert one after another or even merge different files...
I use DVD2SVCD for the job (which does convert avi>vcd/svcd/dvd ) You can get it off doom9.org [its freeware]. It works very nicely but requires an external encoder from CCE, TMPGEnc, Canopus ProCoder, or QuEnc.