After last year’s Oscars, Demi Moore co-hosted Madonna and Guy Oseary’s annual after-party. But this time around, the “Margin Call” star was sidelined by rehab at an undisclosed facility. That didn’t stop her ex, Ashton Kutcher, from kicking up his heels at Madge’s bash till the wee hours. The “Two and a Half Men” playboy partied at Oseary’s Coldwater Canyon mansion till after 4:30 a.m., spies said. Also there were Leonardo DiCaprio, “W.E.” star Abbie Cornish, Michelle Williams, Salma Hayek-Pinault, Heidi Klum, Emma Stone, Mila Kunis, Sandra Bullock and Jonah Hill. The Material Girl’s dancers got the party started by getting down on the dance floor.