Enhancements which you can use with transaction CMOD exist for the shipment.
You will find a more exact description of the individual enhancements within the transaction SMOD as documentation on the respective enhancements or the individual function modules.
You can display all enhancements in the area of transportation by choosing the F4 help in the "enhancement" field. You then enter V56* in the field "enhancement", and choose execute. If you enter V54*, you will receive a list of all the enhancements for the area of shipment cost processing.