httpd.conf question / subdomain

I’m ready to reinstall the multisite. In the WordPress All-In One For Dummies I’m told to open the httpd.conf file so I can enable the wildcard subdomains in Apache. HostGator support told me I can’t do that without affecting everyone on the shared server.

He told me I had to use the cPanel > Add Subdomain. My question is this, when I use the add subdomain do I still need to include the *. ?

Using cPanel, my addition would look like this if I don’t add the *. :
girlsfootballshirts.pigskinfanaticblog.com

Or should I add the *. like this:
girlsfootballshirts.*pigskinfanaticblog.com

Or this:
*girlsfootballshirts.pigskinfanaticblog.com

I have to enter each domain in a rectangular box, the . isn’t inside either box, it just separates the two rectangular boxes.

Can you help me understand what needs to be done here?

Thanks