Well I'm guessing you know basic html/javascript so I'll try my best to explain.
On the page that you want the link to be on to your new page put somethin sort of like...
<script language="JavaScript">
<!-- Begin
function popUp(URL) {
day = new Date();
id = day.getTime();
eval("page" + id + " = window.open(URL, '" + id + "', 'toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=0,width=800,height=600,left = 120,top = 75');");
}
// End -->
</Script>
.... something like that in the head tags, change the properties you need to to fit your website.
For the link that you want to open the new page put something kinda like...
javascript

opUp('main.shtml')
Obviously changing the page name to whatever your page is.
Then on the page that you want to open up put the following in the head tags.
<script language="JavaScript" type="text/JavaScript">
<!--
function MM_openBrWindow(theURL,winName,features) {// open a new window
window.open(theURL,winName,features);
//-->
</script>
I'm not sure if you need all of that but that is the way I do it if I understood what you wanted done. If that isn't what you meant then explain again, also if that isn't right then someone else can correct it.