For displaying one web page within another look at using frames (or an inline frame - iFrame)
The second part of your question I think is asking to be able to display the link in a separate window. To do this, use the target="blank" attribute in the anchor tag. to set the size of the child window you will need to use javascript:
<script type="text/javascript">
function showPopup(url) {
newwindow=window.open(url,'name','height=190,width=520,top=200,left=300,resizable');
if (window.focus) {newwindow.focus()}
}
</script>
So just call the showPopup method from your anchor click event
<a href="http://www.yoururl.com" onclick="showPopup('http://www.yoururl.com');">link text</a>
Ideally you would move the javascript so that it is no longer inline, but this should work.