Split AVI with subs to DVD

[Spacedementia87]

I have an AVI that is split into two files.

I want to make this into a DVD.

Normally i would join the 2 halves, convert to MPEG2 with TMPGEnc then burn with TMPGEnc DVD author.

However because this has the sub file (it is spirited away so i need it!) I am not sure how to do it.

First of all joining the two halves means the sub file is now useless because of the frame numbers in the second half.
Then how do i make it so the subs are on the DVD?
Is it better to embed them to the AVI then convert or shall i keep them seperate?

[Abond]

Proceed like usualy converting video to mpeg2. Join the sub files to one file with subtitle workshop applying appropriate delay for the second part. Use DVD authoring program that support subtitles (TDA doesn't support them).