Using wildcards in Find and Replace (Mac OS app)
macOS's built-in text find and replace, NSTextFinder shown below, does support wildcards available from clicking the search button and choosing Insert Pattern (⌃⌥⌘P).



Other third-party search dialogs may support regex search. For example, in Scrivener, which is developed by the same company as Scapple, you can perform a regular expression search — [0-9]{3} matches a digit 0-9 exactly 3 times.