how to make withholding tax calculated on invoice net

Hi,

we have an invoice with VAT and need to Calcuted on invoice net just without VAT Amount.

EX:

invoice line: 100

VAT: 14

invoice Total: 114

withholding Rate is: 3%

Expected Behavior:

withholding should be on (invoice line ) 100 to Equal 100*3%= 3

Current System Behavior:

withholding should be on (invoice Total ) 114 to Equal 114*3%= 3.42

Thnkas in advance.