Back in the day there were several campaigns made, which originally been compatible with the MC2. Few of them later on been converted under MCO specifics, one under MC2X. Basically new versions doesn't work with the original and I'm not sure is it ether possible or not to convert them back. Campaigns names are:
1. Desert Fox, 5 missions.
2. Lasko's Legion (MCO), 12 missions.
3. Day of Heroes (MCO), 15 missions.
4. Mercenary's Star (MCO), 9 missions.
5. Liberation of Volstand (MCO), 23 missions.
6. Clan Eagle, 18 missions.
7. Wolf's Dragoons (MCO), 21 missions.
8. Rebirth of the White Company (MC2X), ? missions,
9. Liao, ? missions,
10. Solaris VII Arena, 11 missions,
11. Training Day, 5 missions,
12. The Canis Epsilon Two Incident, 4 missions,
13. Clan Flat, 8 missions,
14. Clan Invasion, 8 missions,
15. March To Terra, 22 missions.
+ 16. Exodus, 30 missions.
17. Clan-House Eagle, ? missions.
18. Operation Fimbulwinter, ? missions. Was not available on English.
Originally several of them been here:
https://web.archive.org/web/20030210095152/http://strategyplanet.com/mechcommander/, section "Downloads" -> "Campaigns".
In total, if not count recently recovered original version of
Magic's "
Exodus", there are about 17 campaigns, which contain more then 161 missions, that can be count as a lost one... unless if somebody still have some of them around and can share in this topic, so I'll reupload them on the Google.Drive.