If you want to modify your own code to include wild card then try this
"^(\*\.)?([a-zA-Z0-9]([a-zA-Z0-9]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,6}$"

I'm too bad with regex, but lets give it a try.
According to mampakhas regex, it will also accept
apple.com

I'm not sure if thats allowed. This is modification to mampakha's regex..check if this one works
^((\*\.|[a-zA-Z0-9]+\.))+([a-zA-Z0-9]+\.)+[a-zA-Z]{2,3}$

oops too late

anyway herez modified of myself since the prev one of mine will also accept  test.*.appale.com
^((\*\.|[a-zA-Z0-9]+\.)){1}([a-zA-Z0-9]+\.)+[a-zA-Z]{2,3}$

Thanks techGuy for your time, but apple.com is a valid domain according to my requirement.

howard, thanks for the site
http://www.fileformat.info/tool/regex.htm...i didn't know about it.