List Validation - Date Column value required based on another column status

Hey all,

Long time lurker, first time poster!

I'm currently working on a SharePoint site that will look after staff members certification statuses and alert when they have x amount of days remaining.

I wanted to add some validation onto the expiry column, based on the certification column being set to yes.

For example:

Peter Smith has First Aider column set to yes, but the next column then is the ExpirationDate of that column.

Once a certification is marked to yes I would like for the corresponding expiration date to become an enforced value, I've done some digging but can't find a way to do it!

I was going to set it as a forced column, however it then triggers when they're certification status is blank/set to no.

Thanks in advance.