apparently polytrans software is meant to do it but having tested it myself I found it pretty messy. any fcurve data from maya that uses curves on keyframes to describe ease in/ease out motion is translated into linear interpolation when it heads to max. not very effective. however this was some time back (about a yr) so maybe its been enhanced?
outside of that - I think you can only really shift model data from package to package and that has limitations really.
sorry mate - best I can offer :/