as this is not possible by Make Payment routine from within a Puchase Invoice again the Journal Entry comes to rescue
line | Account | Party | Dr/Cr |
-----------------------------------------------------------------------------------------------
line 1 | Payable account of PINV | Supplier (against PINV) | Debit |
line 2 | Payable account employee expenses | Employee (against Expense Claim) | Credit |
the above markes the PINV as paid and creates a liability against the Employee which can be tracked via the General Ledger
This works fine in default currency. I assume we will end up in multi-currency hell once we try to use non-default currencies.