I recall that the original TSM was an app outside of A:M that would read a MDL file and save out a modified MDL. They wrote it in Macromedia Shockwave and basically it was automated text editing.
Now that I know this spreadsheet thing works... I'm thinking TSM2! I think it may be possible to recreate TSM2 as a manipulation done by a spreadsheet.
You could paste your entire MDL into one cell at the top, magic would happen somewhere in between, and then you'd copy out the rigged MDL from a cell at the bottom.
And it would work for both Mac and PC again.
Somebody do that.