How to merge 2 or more shows together?

[zysiu]

Hi,
I don't speak German, so I'm writing post in English.
Any one has idea how to merge two indenpended shows in one? I tried to use "save output to file" for every show, and then put them in one by loading frames. Unfortunately when I'm converting show as one file *.ild or *.fla the lenght of the show is different from original, and the particular frames are shifted
Maybe there is the another way to merge few shows in one?

[-bart-]

Right mouse button in track => [add show]