How to add material to custom material to design table?

I have been trying to add our companies custom materials to the configurations of a part. I have gone to the help section and found: http://help.solidworks.com/2013/English/WhatsNew/wn2013_Configuring_Materials_in_a_Design_Table.htm

However, how do you make this design table command work with a material sub-folder under a main folder? Like seen below:

Would it be: \$LIBRARY:MATERIAL @PARTNUMBER

And then: End Seal Material: BLACK SPONGE  
Thank you for the help!

SolidworksParts And Features