Multi Object vertex snap

I am currently working on a large scale terrain for simulation and I need a 3dsmax 2009 tool that would allow me to snap the vertex of multiple objects (>1000) within a certain threshold. The engine we are using doesn't allow texture blending so we have to apply a second layer of geometry with alpha textures to get decals. As long as the second geometry has the same triangulation and vertex snapped to the first one, there is no flickering. Right now we use Multigen Creator (simulation tool) to do that but since we do all the content in 3dsmax, we are looking for a solution to do that process with max. Merging all meshes into one object and weld verts is not an acceptable solution since i gotta keep all objects separated for exports!

Thanks in advance,