How are you currently generating the list?
Could be umpteen different ways of excluding the creator, which is the best/easiest depends on what you’re currently doing.
Currently I am using Relation which links all posts within a group, then Lookup to extract their emails, then Joined list to pull all the emails together to form the list which is then used in my Zap.
I don’t quite have a clear visual, but I’m thinking that you can probably replace your relation with a query column that filters to exclude the creator. Try having a play with that. If you can’t get it to work, then if you can add a screen shot or two of how this looks in the Data Editor, then I might be able to provide some more specific guidance.
It sounds like too many steps for me, I assume you have some further steps to generate a list before the “Replace All” part. Couldn’t you just use a query with specific conditions to not include the author’s ID/email and then use a joined list?
Lots of ways you can get it… easiest way depends on where you’re getting it from. In this case of mine, I have all the owners of the row (members of a group in which a post was posted) and I remove the user ID from that array. You can now send emails right from glide to all these recipients, without exporting to zapier.