sql - MS Access: Trim a leading character upon input into form field -

i'm building access database, , on main form, have field called "partnumber." want scan data (a part number) field using usb scanner , barcode. however, barcodes include leading "p" isn't in part number, , serves identify kind of object number assigned to. automatically remove p when scan data, database stores , displays correct part number.

i thought using query expression involving mid() , len(), setting control of form field field in query. however, won't let me change or input data in form's table, it's useless records not in table.

any ideas appreciated. thanks!

i vba, in afterupdate event of textbox.

private sub partnumber_afterupdate()     if left(me!partnumber, 1) = "p"         ' remove first character         me!partnumber = mid(me!partnumber, 2)     end if end sub