>I changed the command to edlin, and changed the main.txt file to what you said, and here is the output:
>
>

>End of input file
>*1
>    1:*Standards
>    1:*Main
>*
>    2:*metric
>    2:*e
>*
>    3:*(third line of the original .cfg file)
>    3:*
>

>
>and it just stops there. Doesn't go back to the prompt.

Hmm, try adding a < ctrl >Z after the "Main< cr >" line.

"Main< cr >< ctrl Z >"

Note that's an EOF character, not the literal.

[update]

Scratch the above, it should be < cr >< lf > in each place:

1< cr >< lf >
Main< cr >< lf >
e< cr >< lf >