Editor refuses to handle my paper for “lack of expertise”
Unless you have strong reason to believe this is an important journal for your field, I would be extremely dubious about having anything to do with a journal with such a lack of organization.

Every reputable journal that I have dealt with has at least some sort of process for tracking and handling manuscripts, which includes the ability to transfer manuscripts to the editor best able to handle the manuscript. Thus, no manuscript would ever receive the sort of uninformative and unprofessional email that you report: either you'd be transferred to a more appropriate editor or you'd be clearly rejected.

The "dead end" email that you've received certainly leaves it open that you might email other editors at the journal to see if they will handle your manuscript. I am not, however, convinced that this would actually be a good idea for you to do, and would suggest shifting to a more reputable and professionally run journal.