Use Opt-in button within a membership site to register subscribers for an event

It would depend on how events are managed. I recommend asking in your events plugin’s dedicated support forum for suggestions. It could take the form of a link that looks like a button. The link leads to code that registers the user. This is where help from the events plugin would be useful: how to register a user via code.

To pass on a list, you could have a report page that queries for all registered users and dynamically generates the list. Again, how to make such a query depends on the events plugin.

Thank you for getting back to me

I think I may have confused the issue by mentioning events. The event is an offline real world occurrence so there’s no plugin to manage it!

All I’m trying to do is create a list of subscribers who have shown interest.

So within the membership area of the site there would be a button that a subscriber could press that would add their profile information to a new spreadsheet. I hope that makes more sense.

It’s still make more sense to initially just add their ID to a list maintained on the DB. This could be done by Ajax request or by linking to a custom coded page. Writing directly to a spreadsheet file is not recommended.

You’d then have a back end dialog box somewhere that would initiate the creation of a spreadsheet file on demand. Code would assemble all the needed data and generate the file. Modern spreadsheet files are XML format. You’ll have more options if you look for a plugin that exports XML, which the spreadsheet program should be able to easily import with little fuss. It’s possible to directly write the data as a proper .xlsx Excel file. It’s a specialized XML file format. There are fewer plugins that would do so. It might require custom coding.

This dialog box could then also let an admin manually add or remove users.