Telnet My Modem To Save changes

I have a modem which has telnet access to linux. The linux is embedded in the firmware itself (busybox 1.9). The modem does not allow me saving my changes into it. All the changes was restored back to default everytime the modem was rebooted. I know there is a way for this online but I'm not expert enough on linux particularly in busybox. Things need to be done: Make a simple script or teach me the linux commands, where I can permanently change the settings of the modem Or all that really needs to happen is that: Modem Box settings will be modified and permanently saved when a script is run or after i issued command manually in linux. If you are really confident in your linux/busybox skills and firmware hacking skills, please contact me for the details of the work and I will give you telnet access to the wimax modem so you can check it.