Here's a copy of a CLI screen
C:\DOCUME~1\David\Desktop>type filter.txt
s/\([a-zA-Z]*\)/\1 /
C:\DOCUME~1\David\Desktop>type sedtest.txt
caller20:20:20
called1:30:03
C:\DOCUME~1\David\Desktop>ssed -f filter.txt sedtest.txt > results.txt
C:\DOCUME~1\David\Desktop>type results.txt
caller 20:20:20
called 1:30:03
C:\DOCUME~1\David\Desktop>