As Craig has said it would be easier to copy and paste the batch values from batch table but you need to make sure users can access the custom table in the first place. For example if you are using SE16N to view the table then this transaction may be restricted to general users.
If this is the case then you may need to go down the development route, in which case rather than copying the standard program and adding a button, I would develop a new transaction with all of the functionality that you require.