If you want certain files (but not others) excluded, you must group them into directories, e.g.:
User-agent: *
Disallow: /cgi-bin/
Per robotstxt.org, asterisks are not supported in the "Disallow" field:
Note also that globbing and regular expression are not supported in either the User-agent
or Disallow lines. The '*' in the User-agent field is a special value meaning "any robot". Specifically, you cannot have lines like "User-agent: bot", "Disallow: /tmp/*" or "Disallow: *.gif".
Additionally, there is no such thing as an "Allow" field. Everything is allowed by default, and specific items are disallowed by exception.
References: