Hexapod robot

I'm making a hexapod robot and I need some help with the math for the movement of it.

Here is a bad sketch (I cant draw in paint and I dont have a scaner):

First I'l try to explain the pictures, then my problem.

On the first picture in first row is the leg looked from back, in xy axises.

The fat line is the body of the robot, at the end of it is point "B", place where leg connects to the robot.

Line "c" is the femur, and it is bent by angle "beta" from the robot.

That is the angle at which the legs can go up and down relative to body.

At angle "alpha", line "c" (femur) connects to line "b" (tibia).

That is the angle at which the tibia can go up and down relative to femur.

Tibia touches the ground at point "A".

Distance from point "A" to point "B" is at the doted line "a".

On the second picture in the first row is everything on yz axises.

There you can see angle "delta", the angle at which the body is tilted up or down.

On the last picture in the first row are the xz axises.

There is angle "gamma" (marked as gama becouse I can't spell english good)

That is an angle at which legs are moved forward or backward relative to body.

In the second row is a picture of one more angle (I didnt know enough greek letters at the time I was drawing the sketch, but I'l call it "zeta" from now on)

"zeta" is an angle at which the body is tilted left or right.

I hope atleast somebody will understand my sketch and can help me explain it better to others.

Now let's get to the problem:

I need a forumla(s) that can get me angles "alpha", "beta" and "gamma" if I know angles "delta" and "zeta", 3d coordinates of "A" and "B" and lenghts of lines "b" (tibia) and "c" (femur).

Thank you for reading this, and I am realy sorry for my bad english.