It is possible to redirect subdomains to subdirectories or individual data  to another externally stored shared host.

Example:
http://subdomain.YourDomainByEuserv.com

is to be redirect to

http://www.externalwebspace.net/directory/page.html

Explanation:

In this case the subdomain refers directly to a file in a subdirectory of an external shared host that has nothing to do with the domain by EUserv.

When you call this subdomain it is always called that one file. If you want to call another file directly, it must be created a new subdomain.  

This function ist available in every rate with the functionality Frameredirect and Headerredirect.