I am only interested in a dos-only solution that does not need any kind of extenders... I am reading on sed and it's DOS versions here: http://www.cornerstonemag.com/sed/ but frankly it seems too much complicated for the small/simple use I plan for it... line buffers , operations and all are great , but for more complex jobs...
edit:
I think I found what I need , it is called MiniTrue and from the manual it looks promising:
Example 1 - The original MiniTrue
mtr -rnw * - Eastasia = Eurasia
This will replace all instances of "Eastasia" with "Eurasia" in all
files on the current drive. The -r option is necessary for scanning
to recurse through the subdirectories. The -n option will make
replacements automatically, and the -w option will only find whole
words
edit2: complete success! minitrue 2.02b does EXACTLY and easily the job 😁 anyone interested can grab it here: http://www.idiotsdelight.net/minitrue/
thanks for all the suggestions/pointers/help , if it wasn's for the djgpp/grer/sed/xyz stuff I would have never found about minitrue 😊