The 21-year-old, who arrived for £7 million in the summer from Belgian club Genk, has scored four goals in nine appearances for his new team.
And, after the striker put in a dominant performance against Manchester United, the Scottish boss has hailed his potential.
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"I think he's not just a strong player, his technique is terrific and, for someone who is just 21, he can be anything he wants," Lambert told the club's official website.
"Christian keeps going. He's a brilliant guy as well. His character is terrific but my God, he's a proper No.9. He did give the United centre-halves a run for their money."
The Villans are 17th in the Premier League after allowing a two-goal lead to slip against United to lose 3-2 but Lambert believes that his side can be boosted by the manner of their defeat.
"The players can take great confidence from leading against Manchester United," he continued.
"It will make them grow a bit. You can see they are a young side but you wouldn't have thought that the way they played.
"They played with a lot of maturity, a lot of discipline in their game and I can't fault them for the way they went about it."