Multi-DB Wildcard Settings

I paid someone from the jobs forum here to install the multi-db plugin on 2 of my sites...after he was finished he made 2 test sites and neither one comes up when entered into the browser. He says I have not set my wildcard settings and I have no idea what he means and he said he would do it for me but came back and told me he could not do it below are his last 2 emails to me.

"But I guess,you didn't set wildcart option. So, for example I add mustafa.biznodes.com and checked from database (_c81) tables creating successfully.But site didn't opened."

"I tried (dns settings and httpd.conf) to set it but I guess that's about your server (you can ask your hosting provider) for example when I call the http://mustafa.biznodes.com -> goto http://mustafa.biznodes.com/cgi-sys/defaultwebpage.cgi"

How do I fix this issue?