Hey,
If you're an Administrator you could do this by posting a global announcement, as long as you are able to use HTML, you would use the following code;
HTML Code:
<a href="URL HERE">Click here if you're not automatically redirected</a>
<meta http-equiv="refresh" content="0;url=URL HERE">
Basically, this displays a link if the users browser is unable to support auto-refresh and the next line automatically redirects the page.
All you need to do is replace the two URL HERE with the link you wish to redirect to.