Second Level Subdomain DNS Wildcard
Solution 1:
yes you can do this, you basically need a record (bind format)
*.design.mydomain.com. 3600 IN A x.x.x.x
or in djbdns format:
+\052.design.mydomain.com:x.x.x.x:3600
Solution 2:
You did not indicate the name server you use. With BIND or NSD, which both use the RFC 1035 format for zone files, this should work:
*.design IN A 192.0.2.3