mhh did you read the readme file?
<=== How to use the Auto Lock ===>
First you need to enter the Windows coordinates in File > Settings > Window Settings.
Hotkeys:
ALT + 5 to record Top-Left Coordinates.
ALT + 6 to record
Top-Left Coordinates.
_______________↑↑↑↑↑↑___________
btw hoocrax here is a fail of yours^^
i think it must be Bottom-Right Coordinates.
After you entered the correct coordinates, close that window and press F2 which activates the lock.exe
Then when you want to lock any NPC / Enemy, simple press the ALT key.
Note : Autlock only works for visible NPC / Player.
did you exactly did this? cause at mine it works fine

thx hoocrax for this nice tool^^
otherwise i don't know how to help you...
maybe hoocrax can help you better
Regards