Non recoverable VAT for a specific items and categories

I work in an industry where some items are non VAT recoverable. For example an item costs £100 and the VAT is 20% so the actual unit cost is £120. The client would like to see this reflected in the unit cost. I am not sure on the financial impact this will have on the various T accounts etc. We are considering adding and extension to the cost hook but I'm a little nervous in going down this route. We are on R12 and also investigating if the e Business tax could help us here. Any Inventory accountants out there  ? 

Regards,

Nick