Tagging of transport expenses to the respective tracking codes

Would like to know if there is a more efficient way to assigning costs to the tracking codes?

As of now, I already had the transport costs (Taxi fares, etc.) already properly keyed in. But now would like to have the costs assigned to the respective tracking codes. But I have not found an efficient way to tag it.

Is there a work around?

You would need to edit the relevant costs and complete the tracking code field

The efficient way would be to complete this field during the initial entry