OK, well in e.g.
VirtualDubMod (find it
here) you should be able to open the AVI file. Then go to "Streams >> Stream list" and move the subtitles track up/down accordingly. Press "OK". Ensure that "Video >> Direct Stream Copy" is selected, then go to "File >> Save As..." and save as a new AVI file.
Hopefully the subtitle order will have been changed and VLC will default to the other language.
Cheers, Arite.