Account Assignment category K(Cost center)

Hi Gurus,

We use K while creating PRs, it allows us to put both cost center and internal order. I request you to suggest me a way ahead how we could put a check or user exit within the system which will allow system to take only those order number range that is assigned to statistical order type.

Please sugget as this will really help me to solve a very critical issue....

Thanks in Advance,

Vikash