Hi Mayur,
I would suggest you to define a external number range for this (as internal won't be possible) and even help if you define it at Material Type level (using number range object-BATCH_MAT).
And then can use customer enhancement-SAPLV1ZE which has FM- EXIT_SAPLV01Z_003 & EXIT_SAPLV01Z_004 to write your own code.
Thanks.
Kind Regards,
Anup