Cell spread and buildings with large foundations

[blackheartstar]

Correct me if Im wrong but the Cellspread= tag applies damage to multi-cell founded buildings once per cell it occupies? Basicly Ive found if you have a Damage=100 weapon containing a CellSpread=9 Warhead with PercentatMax=1 (assume 100% vs everything) and set if of on a Soviet Powerplant it takes a full 600 damage instead of 100. Is there any way to make a warhead only apply damage once the first time it encounters  a multi-founded building in its radius? Or do I need to hit the wishlist?