Manual entry of vat purchase and sales

Dear All,

I am using Tally.ERP in Ethiopia but there is no Statutory Compliance and VAT Class available for the country Ethiopia in Tally.ERP9. So I want to know which ledger accounts should be opened for entries of VAT Purchase and VAT Sales in Tally and under which head. And how would I calculate and do entry of VAT Computation. 

Please help me and oblige.

Thanks and regards

Ajay Singh