When you are working in an assembly you can use the names of parts in the assembly as the value for the "object_name". For example, consider the following part structure:
Given the part structure shown above, all of the following formulas would be good examples of valid cell contents: =@MASS3D("sub_comp.prt", 1, 2 )for a sub assembly =@MASS3D("sub_comp1.prt", 1, 2 )for a component =@MASS3D("SUB_COMP1.PRT", 1, 2 )case insensitive for names