How to create Interna; POs?

HI Exerts,

We want to create some POs for Internal purpose only and identified it separately like "Purchase Order - In-house" etc.. Against those PO purchase will not be actual but for receiving stock only and with the cost assigned to it being cost internally incurred to carry this activity. For receiving stock we don't want to use Misc Transactions. The identification is vital to keep them not only distinct but never be part of purchases in view of sales tax and income tax issues because if the same in any form remains part of normal PO cycle that the Tax authorities will never listen to us.