creating an asymmetric viewing frustum

Hey everyone, Ive got a system ive been working on for what feels like years and i feel like im so close to completion. I have managed to obatain a users position in a given physical space and have interpreted this to an XYZ co ordinate. This co-ordinate is translated into the unity co-ordinate system and is currently moving a camera (locked with lookat. this is controlling the pitch of the camera) within my scene.

everything works up to the point of manipulating the cameras output to create an off-axis projection.

so i have implemented the code for the custom projection matrix from here : http://unity3d.com/support/documenta...ionMatrix.html

My real question is what manipulations would i need to perform on the code to obtain the correct anamorphic distortion so the user sees the image correctly based on there perspective.

I basically suck at matrices and have realised this now but if anyone could help me to understand the relationship between the cameras XYZ position and the matrix to enable the distortion i would be really grateful.

Ive been tearing my hear out with this projection matrix stuff so any help would be amazing.

just a litle background:

the display is a montior layed on its back and facing right upwards (layed on a table) The user walks around the table to view the object in 3D. Y co ordinate is up.

Thanks! K