VAT Invoice with CIS Deduction

Hello,

I have a UK client with the following scenario.  Received an invoice with two lines.  Labor at 11,250 pounds and materials at 44,632.62 pounds.  This invoice needs to have a CIS deduction on the labor of 20%.  What is the best way to calculate and record the CIS 20% deduction while still properly recording the VAT amount?

Thanks