I think the name of the editor is EDLIN

I know a guy that wrote a mine modelling program in Fortran using EDLIN!

>>That looks like it will append to the beginning of the file. I need to replace the first line.
>
>OK, how about this then. Create a main.txt file containing:
>

1
>Main
>
>e
>
>

>
>And then:
>
>

edline config.cfg < main.txt