import files into SW PDM with certain custom property

there are some part files and assembly files are improted into SW PDM. we imported files into PDM by pack and go. usually there is no custom property in these files. so when we set the material of part, and it doesn't show on the custom property of files. and we also can't have the data on the data card of the file. how to work out the problem? 

the custom property of these imported files is so different from the our part template in PDM. any idea on unifying these two?