Question about a move motion

[Durzo]

Hey, I've been practicing on my ralf for quite some time now, and i've gotten a few basic combos down like down kick punch ex Vulcan Punch(i think thats the name) then into another Vulcan Punch ect, but one move that i see from online combo videos in the one where you do   Charge   Punch, now my question is wtf is the secret to that?! i cant ever seem to get it out on a whim and when i can sometimes do it its cus i've held back for a while, too long in fact to even use it into a combo, so im hoping someone could help me with this dilemma. Also, if someone could help me with my lon i cant seem to find good moves to link other then his                                 ,