His ability to keep knocking you back to the ground is totally dependent on his ability to predict your movement… generally, this is a rock / paper / scissors scenario. Since I haven’t been in quite your situation, here are a few theoretical hints.
First, if you make it to the super jump screen, block his Gun, then immediately dash or drill. Her air dash is extremely useful, because it can bait out commando, then give you the opportunity to really follow. If he throws the mine, you can drill under it, probably.
If you can fake him into superjumping without you, you can launch a Kobun, then try to catch him as he lands. The s.hk might be a good idea, whatever… He can’t really intercept you, and his lack of aerial mobility means you should be able to meet him on the ground. Just don’t get caught with a jump-in.
If you can do any sort of dash on the ground, you should be able to get a little closer to him… The important thing is not to get gunned. Do it at the beginning of his jump. Don’t drill, though, because that’s a quick recipe to be AHVB’d.
Consider this… in a situation where he has 1/8 life, if you can catch him with one combo, you can kill him. You know that, and he knows that. If you’re desperate to catch with the combo, then you’ll make mistakes he can capitalize on… Be patient, don’t panic. If you get sloppy, he’ll kill you, period. There is no such thing as a “lucky hit” on an extremely patient Cable.
In the rare event that you can catch Cable and Capcom with the ground drill, mash the bejeesus out of the thing, then King Kobun it. He can’t AHVB, and if you did it right, he can’t jump out. Even if he pushblocks, so much the better… the Kobun shows up where you want it (with the added stun), but you’re a screen away. You get to do whatever you want, without him getting the chance to counter you.
That’s my only advice… but not having an awesome Cable around makes it harder to test these in the arcade. Good luck… this isn’t an easy match up.
Tron Jon