The W.B.A. striker has scored 4 goals in 12 games since signing on loan.
"Craig has been superb since coming here and he is a great lad, obviously we would love to bring him here permanently," Warnock told the Croydon Advertiser.
"I don't really want to bring in too many players in January - but if I can bring in Beattie I'll be happy. A lot depends on who goes out, we have to get players out before we can bring players in."
Meanwhile, Warnock has opted not to hand sacked Walsall forward Ishmel Demontagnac a contract following his trial spell.