The charity has lodged an appeal with the charity tribunal against the commission's reaffirmation in August that Catholic Care could not change its objects to allow it to prevent gay people from using its adoption service.
The regulator reaffirmed its decision, which it originally made in December 2008, after being asked by the High Court to review it.
Benjamin James, a partner at law firm Bircham Dyson Bell, which is representing the charity, said he believed that when it reaffirmed its decision the commission misinterpreted the High Court ruling.
James, who is acting as Catholic Care's spokesman, said the appeal asked for the case to be transferred directly to the Upper Tribunal.
He said the tribunal could quash the commission's decision and ask it to allow the charity to restrict its services to heterosexual couples. If this did not happen, he said, the case could go to the Court of Appeal and the Supreme Court.
The commission has 28 days to set out the grounds on which it will defend its decision. A spokeswoman for the commission said: "We are aware of the appeal and we will submit our response by the deadline."