Just in case:
Wildcard for *.xxx.com will not stretch into subdomains to cover *.intern.xxx.com.
Nor will it work the other way around...
Wildcard for *.intern.xxx.com will not shrink down into parent domain to cover *.xxx.com.
In short: The "asterisk" will equate to all letters and number (and even hyphens and underscores).
But the "asterisk" will never include/cover a "period" nor an "empty" entry (like: xxx.com).