Thank you for your help Lynne. You're probably a good teacher, because you pointed me in the right direction, without giving me the answer immediately
Code:
<form name="MyAT" method="post" action="search.php?do=process">
<input type="hidden" value="process" name="do"/>
<input type="hidden" value="1" name="quicksearch"/>
<input type="hidden" value="1" name="childforums"/>
<input type="hidden" value="1" name="exactname"/>
<input type="hidden" value="" name="s"/>
<input type="hidden" value="0" name="showposts" />
<input type="hidden" value="$bbuserinfo[securitytoken]" name="securitytoken"/>
<input type="hidden" value="$bbuserinfo[username]" name="searchuser" />
<input class="button" type="submit" value="My Active Topics"/>
</form>
Now I just need to change the button into a textlink with javascript