The problem is that your original link isn't specifying the protocol.
<a href="www.magpie-store.com"> isn't going to work - the browser interprets that as a reference to another page in the current context, so the full URL it ends up building is relative to the LJ page.
You need to fully specify the hostname to get it off LJ: <a href="http://www.magpie-store.com"> or <a href="http://www.magpie-store.com/index.html">
no subject
<a href="www.magpie-store.com"> isn't going to work - the browser interprets that as a reference to another page in the current context, so the full URL it ends up building is relative to the LJ page.
You need to fully specify the hostname to get it off LJ:
<a href="http://www.magpie-store.com">
or
<a href="http://www.magpie-store.com/index.html">