[AccessD] Updating a value in a subform

Having a blank moment here

I have a form with a filtered subform (BomtypePForm) and in that subform
(BomtypePForm) are 2 fields (AS_PART_CODE and AS_QTY),
In the subform data are 4 records SCRAP, LABOUR, OVERHEAD and DELIVERY
along with there qty's.

I would like in VB to update SCRAP AS_QTY to a value, LABOUR AS_QTY to
another value etc..etc..etc..

How do I find SCRAP in field AS_PART_CODE in subform BomtypePForm and
update the relevent AS_QTY.


TIA

Liam