Thanks for your speedy feedback. Yes, if I wanted to avoid drag and drop, then what you proposed would work.
However, the requirements as stated in the first post was to enable an end user "who is creating a Purchase Requisition via ME51N to adopt line items from a Purchasing Contract via the Document Overview screen, clicking and dragging the selected items into the Shopping Cart". I was quite explicit as to the behaviour I was attempting to achieve.
- ie: to enable drag and drop, not avoid it.
Much appreciated,
Bruce