How to Delete Users based on IPAddress
 

I have obviously had some "bot" doing registration on my site.
I am using the image verification routine, but they are obviously getting past this.
I have entered the IPAddress in my .htaccess file as "deny".
This should stop any more coming from that IPAddress.
I have implemented the additional user field asking for verification of a certain character in a specified word.
That should reduce the ability for a "bot" to register.

But now, I have over 200 registrations (I allow open/free registration) all from this
specific IPAddress.
How can I do a mass delete?
(I could write a SQL Query to do so... but I'd rather use the "system").
If I use the CPanel "prune users" facility, I can detect who the users are, but when I select "delete" from the drop-down list of actions, it deletes the one I have selected immediately.
I want to be able to check a whole bunch off, and then delete them at once.

Thanks for any help