include newfile include in.run2
This command opens a new input script file and begins reading LAMMPS commands from that file. When the new file is finished, the original file is returned to. Include files can be nested as deeply as desired. If input script A includes script B, and B includes A, then LAMMPS could run for a long time.
If the filename is a variable (see the variable command), different processor partitions can run different input scripts.