Newb Charge/Combo Question

Hello all,

I am trying to figure how to effectively Combo into Charge Specials. From a glance, it seems like I would basically need to be holding back or down-back throughout the entire combo, until I cancel. Is that correct?

Here is an example of a basic combo I am trying to hit with M. Bison:

Cr. LK, CR. LP, St. LK xx LK Knee Press

Does that mean I am holding down-back for the first two moves, then back for the third, and move forward into the cancel? If so, I am having a heck of a time trying to execute it. It feels like I am moving backwards during the third move ( LK ), which is not great for such a short-range combo. Maybe I am just not hitting the LK fast enough? Is it possible to come up for the cancelled move without moving back at all?

Thanks for any advice!