How to create & save multiple silence tracks in batch mode

Audacity: 2.0.3
Windows 7 Home Premium x64 SP1 Build 7601

My project is related to video subtitles.
The number of subtitles per episode may be in 500 - 1100 range.

I can convert each subtitle to individual track in mp3 or wav format and
have length for each track.

I can compute length of silence that should be between subtitles
and create a list of silence length.

For instance, this list may look like this:

Track Length, ss,ms
001 01,720
002 02,040
… …
… …
499 04,720
500 02,001

My goal is to create a single audio track with silence and subtitles in right sequence.

Having silence tracks, I can sort them with my sub files and merge all files in one track.

I figured out how to generate silence manually.
However, doing this hundreds times per episode is very laboring task and seems unreasonable.

Is there a way to use a batch processing to accomplish my need?

I will greatly appreciate any help.