Thanks for your help.This is one big step closer to the solution.
With the line value_template: ‘{{ ??? }}’ I get error message to check my config, if I just delete this line I receive the value from the last line in text file in HA sensor as expected.
I can also run the command: powershell -command “& {gc ( gci C:\logger -recurse | sort LastWriteTime | select -last 1).fullname -tail 1}” in command promt to verify this.
But when I run your last suggestion I´ve got som error messages from powershell, se below (HA i doesn´t read any value with this command line):
