Bottacco

You are right. It didn't occur to me to use ⌘A on an empty field. Thank you very much for your help, but I hope that the behavior with regex with normal things like \t and \n becomes standard. Cheers

Thank you very much for your help @deanishe. I have found an old comment by @Andrew stating that Alfred uses NSRegularExpression for regex search and replace and that \n in the substitution field is not recognized because the \ character is taken as a literal. The solution offered by @Andrew is to use Alt+Return instead. I have tried it and it works, but now there is a second problem: once you input Alt+Return in the substitution field there is no way to delete it because it doesn't appear in the field, so I had to delete that element in the workflow and recreate it. The post where Andrew talks about it is here:

I am trying to create a simple workflow to copy a selected row in Excel and place it on the clipboard after changing the tab character that separates fields in a return character. I am trying to use a conversion with regex of \t to \n but it is not working. Any ideas?