Setting the subdomain as a variable in apache config to be used in the same config file:

1. How to define dynamically the subdomain of wildcard address as a variable in apache configuration file ?
2. How can I call the enviroment variable in configuration file of apache ? This option here doen't work: Create an Apache SetEnv variable with the subdomain name in case of wildcard It seems it doesn't work.

I've tried:

setting the enviroment virable:

• SetEnv SUBDOMAIN subdomainx
• SetEnvIf Host "^([^.]*).domainx.tldx$" SUBDOMAIN=$1
• SetEnvIf Host "^([^.]*).domainx.tldx$" SUBDOMAIN=specificsubdomainx
• Define SUBDOMAIN %-3

retrieving the variable in the same config file:

• ${SUBDOMAIN}
• %{SUBDOMAIN}
• SUBDOMAIN

Please help, Its freaking me out. Thanks