I figured out how to do something that works for me.
I have Exec-PHP enabled so I included this in my tagcloud page.
<link href="tagcloud.css?<?PHP echo date("j/m - 20y"); ?>" media="all" rel="stylesheet" type="text/css" />
Content of tagcloud.css
.tag-link-41 , .tag-link-73 { display:none; }
Not automatic, but the end result is okay.
