anchr tag replace

Its a long story, but basically, theres some code we cannot get around that is taking anchor tags such as <a href="#sat"> and turning them into <a href="http://host.com/folder/file.html?var=var&var2=var2#sat>. I need to undo this action with a pattern match on a large body of content with "". Can this be done. Here are further details: I need a regular expression that will recognize the following where #anchor can be anything such as #sat or #sunday or #lastpage: <a*href="http://*#anchor"*> And turn it into this: <a*href="#anchor"*> What I am doing is removing the http://host/.../.../file.html?variable&variable that immediately precedes the #anchor.