Transfer Sold-to-party number to FBLN5N

Hello,

Business requirement is as follow. User wants the Sold-to-party number, to be shown/displayed when executing FBL5N transaction,

I thought this could be achieved through user Exit EXIT_SAPLV60B_008 but technical team said it could not be achieved. Does anyone have a clue, on how to sort this out?

Thanks in advance!!