please advice me on my billing scenerio

Hi sd gurus

Here I am facing a typical scenerio for billing. the scenrio is as such. I have a warehouse where inbound and outbound process are happen. I am making inbound by two transaction (po-me21n -vl31n -inbound delevery) after goods recieve I want to charge the customer for my inbound charges( charges includes from port---my warehouse like transporation charges survey charges etc) so i wanna to billing the customer after I recieve the goods how can I map in to sap. please please suggest me. your advice is highly solicited.

thank you.