How to get a matrix into matLab from a txt file

I have .txt file with lot of data, tex and numbers. When I open the .txt on matLab i get 63630 lines. Starting arround line 1200 until 63630 I have a matriz on that file. Using that matrix I have to create a image.

To create the image I've done this:

image(matriz,'CDataMapping','scaled'); colormap(gray);

but I'm not able to define the variable 'matriz' from the .txt file, can someone explain me how I can choose and say to matLab that those specific line are suposed to be a matrix?

[Walter Roberson]

The lines that you do want, what format are they, and which parts of them do you want read in as data?

[Jan]

A summary: You want to import the lines 1200 to 63630 from a text file to a matrix. Correct? Please post one of these lines, wuch that we can see the format.

What have you tried so far and which problems occurred?