Shape keys and lattices in the GE?

When making a shape key for an animation to be in the GE… is it possible to use the mesh data from another mesh as a new key. eg. a mesh that has the same number of vertices but is deformed with a lattice?

Is the only way we can animate the vertices for shape keys by manually grabbing then and scaling/moving them?.. never mind… sculpt works on locked shape keys… I can use that to get the shapes I want… sweet… allthough being able to use a lattice to create a shape key directly would be cool too…(I don’t mean linking an object to a lattice and deforming it)…

Any other ideas on good ways of moving vertices when creating shape keys for the GE?