@Carl Love Thank you very much for this good answer.

@Carl Love 

Thank you very much. I have a general question. I begin my procedures usally as the following: for example "variables:=proc(F,L)" . But I think that you begin with another form. Is this true?

@Carl Love  You are right. it was successfully implemented!

@Kitonum Thanks for this answer. Now I am trying to implement a general method for this. Since, in the implementation of my main algorithm, I need to form the matrix coefficient of some polynomial ideal  as above.

@Carl Love You are right. The Acer's way is generalizable for my purpose,

@Thomas Richard 

Thanks for your comment. I need this in Groebner Basis. Do you know comprehensive Groebner Basis?

@acer 

Thank you for your replying. It seems to be good but I want a general way for extract parametric coefficient from a parametric polynomial matrix.