In a previous post, I've described how you can use Tcl shell to upload text content into the router's flash if the router has no connectivity to a suitable file server (or you don't have FTP or TFTP server handy).

The trick works flawlessly, but typing the same obscure Tcl commands gets tedious after a while, so the first time I had to use this solution to develop a Tcl script, I quickly wrote another script that takes a file name as a parameter and hides all the other murky details.

To use it, transfer the contents of storeFile.tcl to the router's flash (using the previously described trick), follow the installation instructions in the Tcl source, and you're ready to go.