I've searched the LunarForums for an answer, and apparently a lot of people have had this problem, but I still have not found a solution.

I work for a company that sells marine products and services. The primary domain is svendsens.com. We have a subdomain, svendsensmarine.com, which we use for an ecommerce site. That site uses Volusion, so most of the pages are built on the fly and don't exist as entities.

Years ago (before I came here), one of the vendors whose products we sell, Gill, demanded that we split all their products out into a separate online store since we couldn't sell anything on the same site as competitors' products. So we did that, and created yet another domain: svendsensgillstore.com, also run with Volusion.

Now, we have dropped the competitors, and I have brought all the products from the separate Gill-only store (svendsensgillstore.com) over to our main online store (svendsensmarine.com). What I'd like to do now is redirect the domain svendsensgillstore.com to point at svendsensmarine.com, so that any links to the Gill store out there will bring visitors to the main svendsensmarine.com site.

I have tried using the Redirect function in cPanel (tried to attach screenshot, got an 'attachment directory not writable' message - ??). No dice. I have tried using Redirecting in the .htaccess file. Nothing. When I asked LunarPages customer service, I was told they don't give this kind of support, and to come ask you guys. So here I am.
Caveat: I am a graphic designer and art director. In this lovely economic climate, like so many people out there, I have had to take on more responsibilities - including the webmaster chores around here - and I'm the first to admit that the world of domains, chmods, PHP, and the like makes my brain come to a complete halt. So for you tech masters, forgive my newbie ignorance - but if you can solve my problem easily and quickly, I give you full permission to cap on me for it!
Thanks very much for you time - Sarah.