@echo off & setlocal
set /p last=<lastrun
set /a last=(last+1)"%%"10
:: put the actual command here. not aquainted with Perl syntax
perl perlscript -input=perlin%last%
>lastrun echo %last%
::==== end script
disclaimers etc: this only works if it runs every day. If you skip a day, it will still
run the file that should have been run the day before. use task-sched to avoid this.
You will need to put the 10 textfiles into names with 0-9. f/e: file for day 1 would be like perlin0. File for day 10 would be like perlin9.
This is lame, but best I can do with what you gave and what I got.