If this is ticketless travel funds from a flight you cancelled or re-fared, no way around it. Has to be a flight booked in your name. You can book a ticket for a friend with your Rapid Rewards points.

From the Southwest website:
"Unused Ticketless Travel Funds: Southwest Airlines accepts unused ticketless travel funds for Passenger travel purchased through Southwest Airlines, excluding the Southwest Airlines Group Desk and Southwest Airlines® Vacations. Unused ticketless travel funds may be redeemed at Southwest.com, through Southwest Airlines Reservations, and at Southwest Airlines Ticket Counter locations. All travel involving unused ticketless travel funds must be completed by the expiration date. Unused ticketless travel funds may only be applied toward the purchase of future travel for the individual named on the ticket."