Comment 3 for bug 895091

isn't that already possible?

i remember allowing infantry units to occupy UC-buildings and there is a rulesmd.ini-flag which defines the weapon used by this unit in UC.

[E1]
...
Occupier=yes ; I can Occupy UC buildings
OccupyWeapon=UCPara; The weapon I use while Occupying. Defaults to 0 (Primary)
...