KB001692: What are the Steps to Print a Chromatogram in a Particular Size? - MS ChemStation 

This can be done by executing a command from the Command line.
To print the intensity range 0 to 500,000 for retention times of 3 to 5 minutes, type "draw 2,r0,3:5,0:500000" in the command line and then press ENTER. This displays the requested range in the top part of the screen (second window). You can now print using the normal procedure. That is, open the [File] menu, click [Print], select the selected window, and set the window # to print as "2".