This plug-in uses Regular Expressions (see standard syntax in Wikipedia) to pair host domain names to IP addresses.
This gives you much more flexibility than simple wildcard records.
To setup a new Regular Expression plug-in instance; in the Simple DNS Plus options dialog / Plug-ins section, select the "Regular Expressions" component and click the "Create new instance..." button.
Here is a simple example:
This will cause requests for anything under "mydomain.com" starting with "asia" to resolve to IP 18.104.22.168.
That would include for example "asia123.mydomain.com".
Requests for "europe..." resolve to 22.214.171.124, requests for "america..." resolve to 126.96.36.199, and anything else under "mydomain.com" resolves to 188.8.131.52.
Regular expressions are compiled when the server modules loads them and therefore run very efficiently in Simple DNS Plus.
NOTE: Keep in mind that the dot (.) character has special meaning in regular expressions (matches any character), so when matching multi-segment domains names, the domain name dots must be enclosed in square brackets [.].
For example to match exactly "something.example.com", the regular expression would be "^something[.]example[.]com$" without the quotes.
The regular expression equivalent to the wildcard record name "*.example.com" is ".*[.]example[.]com$".
For more information, please see the following knowledge base article: