This is a simple export out as a .ma file. The ASCII file is read natively inside of Maya. You would need to export out the luma matte as you say and apply a locator to the geometry to store the 3D translation geometry. Back in Malta I needed to do this to track a stupid toothfairy to apply pixie dust with Particular. Make sure you name the respectively "null_0" and so on based on which one. You might have to bake out the data on the locator as well. I onestly can't remember but it will work.