TAX ON (NON INVENTORY ) Iprocurement Item ??

Hi ALL,
 

Let Assume a PO contain the No. fo Non Catalogue Item and what i want is to Apply the diffrent tax for each Line therefore I am not getting how to cater this things ??
 ON PO Haider I can Apply the Tax but on Line there is one time is of Goods and Anotehr Item is of Services. Therefore what should be the Line of action in this reagrds ??

We dont have defeind Item on the Back hand it just a category and to Apply the Tax on Category how it is possible ?

Regards