Automated ClockworkMod Recovery script (extendedcommand)

Hi, I want ClockworkMod Recovery to run some commands when it boots. This can be done by placing a file named extendedcommand in /cache/recovery/.

My problem is, I cannot put extendedcommand in /cache/recovery/ via adb push without root.

Is there a way around this? I'm basically creating a root installer, hence why I cannot have root in the first place.

Is it possible to get ClockworkMod Recovery to check for extendedcommand in the SD card or another folder when I can push via adb push?

Thanks.