I don't think you can import the data with the mapped faces from Picasa into the Lenovo Photo Master. These applications are not compatible one with each other. What Lenovo Photo Master has a differrent algorithm to detect faces and map them accordingly. I am pretty sure that you will have to map all the faces one more time an then save images individually.
I know that Picasa isn't supported anymore, but I suggest you keep using it instead of Lenovo Photo Master. Both apps are good, but Picasa is more powerful