Thanks Denisyour first paragraph makes perfect sense Im a little unsure with regards to your second paragraph but we do not have a large database, so hopefully the above should be okay. Many thanks  C 

Hi DenisThank you for your prompt response, I have done just that. and that seems to work.To further specify the URL as above should the query be as below?  

Hello Is this possible to do at campaign level rather at email level?So to target all users that have clicked a specific link in any email in a particular campaign?