How do I add a user inputted stop to the code running?

[JBEDsol]

How do I add a custom type of CTRL+ALT+DEL to my code.  Some of the things I've written code for can take a while.  To speed things up I've added App.screenupdating=false.  However there's times where I just need to see if it's running or maybe something is not quite right and I need to stop the code.  I can easily do this within VB.net but how do I give the user (creating an Addin for the company) a way to do this?

[JelteDeJong]

the progressbar has some functionality that can be used to stop long-running rules. I wrote a blog post about it. Have a look "Stop long-running rule (with the progress bar)."

If you like that you also might look at the next post "Transactions for robust and fast rules". In there you will find a cleaner solution.