Hi,
I do not how much i understand your question still based on what i deciphered i am answering.
You require another column which gives you the account number infoobject as key.
If you are flexible with modeling level changes then you can add another infoobject and map it with the same field with which you mapped ac no.
Now you will have two infoobjects having same data so display one as key and other as text.
I hope this is what you are looking for.
Regards,
AL