Villa have won only four Premier League games this season and, despite an improved second-half performance, are facing a grim battle to avoid dropping into the Championship.
Lambert said: "I'm not sure the situation [on buying players] has changed from Jan 1. There have been things we've tried but money dictates a lot of things.
"You have to play with the hand that you're dealt with. Randy has been great and I've got nothing bad to say about him, it's always good to get support from the people that hire you. All I can do is my best to try to turn it around. Our performance here was as different as night and day but it's the first time I've seen a standing ovation when we've been beaten, especially at home."