Hello Satya,
I checked this requirement and did not find anything relevant.Even for MIGO there is a note 1883420 - In the transaction MIGO only 6 serial numbers can be entered at the same time.So as per my view you can either
1. Create serial no's before hand which you want to paste from Excel or
2. Some custom/alternate development for CO01,discuss with your Abaper. or
3. Raise OSS messge to SAP.
Regards,