Static objects as a spawn point; no, I don't think that's possible. Supply drops as a spawn point; yes, that's possible, but there's no way to have the spawn point activate once the supply drop has touched the ground.
And I've been thinking about this suggestion. I don't think it would work out too well. If you give commanders or SL's the ability to mark the map for artillery, then you could just "mark" an enemy flag without having a spotter in the area, essentially leading to main rape by artillery.