Hello, 
  
Im using  AutoCAD, AutoCAD Mechanical 2009 and Mechanical Desktop 2009 
  
I have parts that have a material assigned to them through the 'MASSPROPS' dialog box.  When assigning the material to a part, material properties associated with that part are assigned as well.  Is there a way to either remove the material assignment or create a "dummy" material with material property values set to 0 and assign this new material to the part using AutoLISP?  If not AutoLISP, is it possible using any other code type?