You have to have the part in your lookup database for the BOM routine to find it. Also, you may want to add a wdblknam attribute to the block. And finally, you can add text to any attribute in your block from the database by using the TEXTVALUE field and separate the attributes with a ; (ie. DESC1="RELAY, LATCH";RATING25="4").
For the TEXTVALUE to work properly, the attributes have to already exist in the symbol itself. I use this function a lot when I create the panel first and then the schematic. In many of my footprints, I have added the following attributes;
MFG01, CAT01, MFG02, CAT02, and then added those items to the TEXTVALUE field.
Ace User since 1998