Vertex groups for face

[Tanelorn]

Was wondering if it was possible to automatically assign the shapekeys to a vertex group that only includes the face on import. As I often modify the original mesh in many ways to create characters. By adding, subtracting, and tweaking the imported topology. Then when animating face expressions I end up with bizarre occurrences in the model. Which can be avoided by by assigning all the expression keys to a vertex group. However doing this by hand is a pain as their are a shlew of shapekeys for facial expressions. It would be nice if it was automated on import.

P.S. This is for import to blender.

Thanks.