Workaround of AP Invoice with Manual TAX Entry

Hi All,

I would appreciate if anybody can help me in this workaround Scenario. I have tried a lot but unable to achieve this through any workaround.

At AP Invoice.. entries should be

Payable Expense      2300  [DR]

Another Expense      20      [DR]

          Liability                                    2320  [CR]

At Payment Time..  entries should be

Liability                    2320  [DR]

          WH TAX (10% of 2300)                                           230 [CR]

          WH TAX (10% of 20)                                               2 [CR]

          WH Sales TAX Payable (100% of 20)                  20 [CR]

          Bank                                                                       2068 [CR]

Please let me know, how to cater out this functionality. I have to withhold 10% on gross amount of 2320.

Another Expense amount of 20 is basically Sales TAX Amount that I need to cater out manually and then withhold 100% of it.  I want accounting entries as mentioned above.