Hi, Luis! I'd suggest the Legs & Glutes workout (on the same DVD as Kick Punch and Crunch), as well as the Hard Core Gym Style Legs DVD. Prepare to have some equipment purchased, such as a band and a stability ball, as well as some light ankle weights.
Also, weighted "step-ups", or what Cathe refers to as "leg presses", where you step up in a slow and controlled manner onto a high step (no higher, however, that a height where your knee goes past 90 degrees of flexion) are proven to be the single best glute-builder. If none of your current Cathe DVDs have those, consider investing in the Pyramid Upper / Lower Body, and the Boot Camp / Muscle Endurance DVDs, because those have a LOT of step-ups / Leg Presses.
HTH -
A-Jock