Some tailoring is needed to fit your environment:
SET /P old=String to replace: &REM Preserve trailing space
SET /P new=Replacement string: &REM Preserve trailing space
REN "%file%" "license.txt.bak"
FOR /F "tokens=1* delims=:" %%A IN ('TYPE "%backup%"^|FINDSTR /n "^"') DO (
IF DEFINED line SET line=!line:%old%=%new%!
If "old" and "new" are always the same, replace the SET /P with simple SETs that don't prompt the user for input.
Change SET file= to represent the file you need to modify several times a day. I used a software license agreement that happened to be in the same directory as the .bat file as a sample file to test with.
Update "license.txt.bak" to properly represent the (backup) file name that should be created.
Remove the TYPE "%file%" if you don't care to see the file after being modified. I put it there as a debugging tool.
When your only tool is a hammer, every problem looks like a nail.