The usage is simple, just add a few units with the "Repair" command to this AI, and if Idle they will automatically repair or build the closest unit that does not have full-health.
Basically if you keep a few builders in this group, everything that gets built automatically gets assisted by these builders, and everything that gets damaged, like laser-towers or vehicles, will automatically get repaired faster.
Downsides:
- When you try to reclaim your own buildings, the AutoRepair group starts rebuilding it while it isn't 100% reclaimed.
- If a unit is under attack you might not appreciate builders going to that scene.
- Offensive units will get healed too, which might not be what you want

Anyway, you can get it at <err I can't seem to post hyperlinks :S, see bottom of post for hints

Just stick it in TASpring/aidll/, and in-game use "Select AI" to create a group of repairmen

As a quick side-note, it's better to add units to an existing repair AI group, than to create a new repair AI group. This is because if they're all in the same group, the AI will optimize it's search routines...
Anyway, have fun with it, and any feedback or recommendations should be posted here :)
The URL consists of thuis <dot> hardijzer <dot> nl <slash> autorepair <dot> dll