Help with copying files to external drive in single user mode

I'm a newbie to Unix and hoping that it will be my saviour when all else has failed.

My "keys [are] out of order" on my g4 laptop and neither Disk Util nor Disk Warrior can fix it.

I'm experimenting in the unix command line (I figure I can't mess this laptop up anymore , and have figured out how to use the cp command to copy the exact file I need.

BUT, I can't figure out how to designate an external drive as the destination volume.

Does this even work in single user mode?

Any advice from Unix gurus on how to salvage this file before I initialize my hard disk and lose it forever?

Thanks! Misho S.

You will need to mount the external drive to make it available for usage.
If you mount the drive under /mnt/external then just copy the files to it using the copy command; for example

coping some pdf files from your current working directory

<command> <file> <destination>
cp tiger.pdf /mnt/external/

This should copy the tiger.pdf to the mounted external drive.
If you wanted to make a folder on the external drive and copy the files to that folder, add the folder name to the destination, example

<command> <file> <destination>
cp tiger.pdf /mnt/external/my-pdfs

thanks for the reply...

I tried the mnt/external and I get a prompt "No such file or directory"

I can find the file I need to copy, but just can't figure out how to send it to my external FW drive.

You have to mount the external device to the location. Just as you would mount a CD or a floppy drive, the external drive will need mounting.