[exim] Regex Parsing help

I'm really not good at regex. And this should be simple stuff. Here's
what I'm trying to do.

I have a list of domain names in a string such as:

set acl_c_domain_list = domain1.com domain2.com domain3.com

The delimiter is a space but I can make it anything. What I want to do
is set two variables. The first variable will have the first domain in
the list, no spaces, (domain1.com) and the second variable will have
the rest of the list items, no leading space. (domain2.com domain3.com )

How do I do that?

Thanks in advance. I'm working on something really kool that I will
share when it works.