Automate track number?

I'm planning to combine albums with 2 discs into one long disc. I want to number all the tracks on the second discs from a certain number.
Example: disc 1 has 6 tracks, so I want mp3tag to auto number the tracks on disc 2 starting with 7.
Thanks!

This function is already built in the numbering assistant.
Alternatively, instead of setting a value manually, you could also select all files from both CDs and renumber them but have the option "Reset counter" disabled.

Automatization would be rather tricky as it is hard to find out, where one album starts and where one ends and whether to seriously renumber the tracks.