Startup script

New in Unix, I am adding a line "route add 57.14.y.y 57.14.x.x" every day after rebooting the system. Where can I add the line so during boot up (the system is re-started every day by design (???) the line is executed? (I tried the /etc/rc2.d/S90 but for some reason the line needs to be added after rebooting and I can't use this file (another problem I need to solve, later).

If S90 is a start up script you built, try moving it to /etc/rc3.d so it gets started later in the boot process - that may solve both issues.

On Linux you can try /etc/rc.local (have no any idea whether this file exists under Unix)
Chech also /etc/rc > This file is responsible for starting/stopping services when the runlevel changes