sequential backgrounds

I have 3 shots I've created in high resolution in Lightwave that I must edit together into a single sequence. My editing program won't preserve the high resolution, so I'd like to do it all in Lightwave.

I can load the 3 shots into Lightwave as movies, or as sequences of stills. But can I set them up sequentially to record out a complete sequence?

I could of course renumber by hand all the stills in shots 2 and 3 to be sequential to shot 1, but that's a lot of time. I can't get LW to export the stills starting at an arbitrary frame number (ie., the one after the end of shot 1).

If I could simply tell the background to switch to a new sequence on a given frame, then I'd be done.

thanks for your time.