In receiving mode edit the part that you did not get the correct qty. Change the qty to the value that you received. Once you click ok you will get prompted to process a split order. Yes will split the total qty into 2 lines with the same PO number and selecting No will remove the excess off of the PO.
Once you have the item on the PO screen just change the REFERENCE not the GL box on the edit view of the item to the GL that is for shop supplies and that will then put the value to that GL instead of putting stock into inventory.
The file access code for the Unlock PO prompt. PTM-FAC is the default, if it is a customer password will have to ask the person that set them up.
PO screen, H for history, say no if prompted for search vendor... Grid search for the PO number or a part number on that PO and hit [F7] and A print PO and say YES to print receiving report.