User exit or Enhancement for Serialization during goods issue for Vl02n

need ENHANCEMENT/EXIT for the below requirement :

Only outbound deliveries to customers require serialization data to be filled in the outbound delivery. These deliveries can be distinguished based on the delivery type.

For this custom coding is required as standard SAP will not cater for this. In standard SAP it is only possible to activate serialization to be checked on delivery level instead of the types of deliveries. In the custom logic it should be possible to define delivery types for which serialization should be checked. Also, in this custom logic it should be possible to determine (based on delivery type) whether it is optional/mandatory to have serial numbers assigned to the materials with the new serial number profile.