In MvC3, Zero can not cancel his jumping H attack into any special moves. The only thing he can cancel it into is his jumping S attack. His jumping S attack can be canceled into a special moves, though, but it has the problem that if it connects as part of an air combo following a launcher, it will knock the opponent to the ground and, most likely, most of the way across the screen, and then it loses its ability to be canceled.
The solution I came up with is to cancel the H attack into the S attack, but then cancel the start up of the S attack into a special move. There is a relatively small window where this works, but it allows you to combo a Charge Shot after, or go for a variety of reset options that you wouldn't otherwise have access to, because the H attack will hit them long enough that they will tech on the ground, instead of in the air like after 2 M attacks.