man xterm
-e program [ arguments ... ]
This option specifies the program (and its command line arguments) to be run in the xterm window. It also sets the window title and icon name to be the basename of the program being executed if neither -T nor -n are given on the command line. This must be the last option on the command line.
This is how useful man-pages can be
Now it's just a matter of editing your menu accordingly.