Unplanned delivery cost for different Vendor

Hi,

For a import PO we need to pay OCTOI to Municipal corporation.

Unfortunately while PO creation the octroi condition was not entered.

Now we need to post a invoice for this and the condition is, we must post this to material.

We dont want to do direct FI entry as then this will not load on material.

Entring Unplanned delivery cost at the time of invoice will not be possible is the Vendor is different.

Any suggestions please...

Rajesh