In case you will need it, here’s a thing that helped me out once. In case you want to append some config lines that you have stored in a file and if you can’t copy it through SFTP, you can make it locally.
To do this you need to start tclsh and create the file puts [open "flash:filename" w+] { now don’t press enter but just paste in your config lines and then } and ENTER. tclquit to exit tclsh.
Now you’ll have your config snippet in flash:filename and you can use it to append to your config. Would be a good idea to check it with more flash:filename just to be sure that you have everything in place and no characters were left outside.
As always, more info on Cisco’s webpage