Prohibit PO creation depending on Material Business Area

Hello,

Is there a way to stop PO creation when a user creates a PO with a material-plant (w/o Account Assignment) that belongs to a certain Business Area?

I tried deleting the valuation area-division-business area at OMJ7 but the problem is that I can still raise a PO, I do get the error during GR, but the problem is that in real life, the PO will be raised to a vendor.