Transfer posting

Hi,

There is a scenario that there are some branches which are considered as sales office. when spares materials are sent to this branches the stock should be available at this branch levels . To do this storage locations are made for each branch. But all this storage locations belongs to a single plant. The requirement is to generate excise invoice when transfer posting using Movement type 311 is done to transfer stock to branches. But no excise invoice is generated for storage to storage transfer in one plant. How can i incorporate this?Please suggest. Also we will not be treating branches as plants.

Regards

John