login link URL

Hi
Is there any simple way to change the url of link "login" in gallery2?
I have a bridge for Joomla, and what i want is when user click "login" link he is moved to my Joomla site.
I want the simplest solution - harcode the new url in <a href='' /> but i cant find where is the proper place to write it.

Thanks for reply
But i found something like that:
In file /modules/core/templates/blocks/SystemLinks.tpl there are two foreach loops. The second one is responsible for Administration, Your Account, Login/ logout links.
So when you change

 {if isset($theme.systemLinks[$linkId])}
        <span class="{$class}">
    <a href="{g->url
       params=$theme.systemLinks[$linkId].params}">{$theme.systemLinks[$linkId].text}</a>
        </span>
  {$separator}
  {/if}

on the following

 {if isset($theme.systemLinks[$linkId])}
        {if $linkId != "core.Login"}
        <span class="{$class}">
    <a href="{g->url
       params=$theme.systemLinks[$linkId].params}">{$theme.systemLinks[$linkId].text}</a>
        </span>
        {else}
        <a href="http://my new funny link"> Login<a>
        {/if}
  {$separator}
  {/if}

then it should be ok (for me it works).
Of course there is a need to change a link, and refresh the theme.
Won't that way cause any problems?