How to generate custom batch name for legacy system transactions

Hi Team,

Need your expert opinion.

We are importing the data from sub system. Batch name is the filed where we are using for identify the duplicate batch names. We are providing the batch name from subsystem, But system is adding journal source and request id to the batch name and importing into the base table. Due to this reason we are unable to identify the duplicate batch name. Can any one have idea that restrict system functinality of adding source and request numbers to the batch name.

Thanks

chandrasekar