CIF sales order when there is a change in Storage location from ECC to APO.

i Team, 

I am looking for the possible options where in when there is a change in Storage location field in sales order, the changes should get CIF to APO from ECC.

I have seen that when there is a change in Quantity field in Sales order it's geeting CIF to APO from ECC & the new requirement is when there is a change in Storage loctation filed in sales order then also Sales Order should get CIF to APO. Please guid me.

Thanks!

Anil Sahni