Questions Inventory ID using combined segments

Hi I'm new to this forum, so please forgive me if this has already been answered (I did search but will readily admit I may have missed it).

But does anyone know if it's possible to combine a field like Item Class (we use a 3 letter code for each one) with a sequential number to get a unique Inventory ID?

e.g. we need all hardware to be HWR-00988 but all Shipping Supplies to be SUP-00989 and so on.

My workaround right now is to create an Attribute called ITEMCLASS and basically mirror the item class codes (HWR, SUP, etc) then add attributes to each Item Class and use the Inventory ID Segment Settings to make it look like it's pulling the actual Item Class. But this only works if you build everything as a template first. 

Seems like this should exist though? I think the data already exists in INITEMMENU.