texturing a matrix at the basic of levels is to load a texture into an image location
and prepare the matrix texture across the matrice's surfaces if there were multiple divisions eg: 10 x10.
save your source file into a folder with a texture file like bmp or png or dds and then create a small peice of code to load in the texture and create the matrix. prepare matrix texture command should make more sense then.
If no-one gives your an answer to a question you have asked, consider:- Is your question clear.- Did you ask nicely.- Are you showing any effort to solve the problem yourself 