Animation Question: How to Lock Down a Character in a Frame?

Inkubo

I'm trying to learn something very difficult. I'm trying to animate a minotaur stomping up some stairs.

What I did was to pose the character with his feet placed as if climbing the stairs, and save that as a pose preset. Then I mirrored the pose and saved it as a second pose preset. Finally, I added a non-essential character to my scene and made keyframes of her gliding to and up the stairs, in order to gauge where the minotaur should be at any time. I found the points she glided to where he should look like the poses I saved, and in each of those frames I positioned the minotaur and applied the proper preset. Now all the remains is to tweak the tweening! It sounds so simple...

So here's my problem: When the character gets to each of those frames I made, the pose he is in is exactly the pose I want. I don't want interpolation to mess with it as I make tweaks to frames before or after it. Right now it seems every frame messes with every other frame as I go in to correct foot slide and placement. It's like trying to mold Jell-O using one finger: every press here changes something there.

Is there any way to make a keyframe that applies to all a character's parameters at once, whether they have been edited or not? That's what I really need on these poses, keyframes for all parameters on all bones, so that if I have frames A, B, and C, I can lock down everything in frame B to keep interpolation from screwing it up as I tweak A or C.