Can we let system set the default subinv in Sales Order line by user item type?

Dear Experts,

The user item type locates in items' attribute, like direct10, direct20.

if we have a reflection tables, like direct10 - Sub1; direct20 - Sub2

can the subinv in SO line be identified by user item type to give default subinv in SO line automatically when we enter item# in SO line?

PS: I tried default rules in OM, but where has no related attribute for user item type.

Thanks,

Steven