Additional Shipping Charge - how is it handled?

[sandy]

Hi,

Currently I am sort of learning the ropes with ofbiz and also evaluating 
fit for a standard trading organization (mostly in-store bulk material 
handling)

One scenario that happens often in such cases is shipping charges are 
not standard and depends on what the carrier quotes at the time of 
picking up packages especially when it is not full container. Towards 
that I was very encouraged to find "Additional Shipping Charge" as an 
option in packing screen. Keyed in some number and that showed up in the 
"facility/control/ViewShipment" screen for that shipping ID. Great!

What I don't see is how is this charged back to the customer. Note that 
I am taking the straight case of customer first paying the invoice 
amount before the items are packaged and shipped.
I was hoping to see something like another invoice created with the 
additional shipping charge and accounted against the billing account of 
the customer. This can also be a case where the actual shipping is lower 
for some reason and there is a refund of shipping charges.

If this functionality does not exist then, I would be interested in 
getting inputs towards how this should be approached. If it is already 
implemented in some other way, would definitely appreciate pointers.

Thanks in advance
Sandy