Using LB_FAILED and change the URI w/o 302

I am trying to use the 'when LB_FAILED' to send requests a pool just for apologies. The issue is that the requests coming into the VS have crazy long URI strings like '/ABC/def/g/hij/klmno/' and my sorry server is running a simple HTML page at '/apologies/apologies.htm' I have configured this directory and page to be the default, so I can hit the server directly at 'http://host.domain.com/' and get the correct content. I have tried a few different variations, and can't seem to be able to change the URI after 'when LB_FAILED' before the request goes to the apologies pool.

Rev 1, I added some logging to see what was being passed

 
 when LB_FAILED { 
 log local0. "URI is [HTTP::uri]" 
 log local0. "$poolname has [active_members [LB::server pool]] members" 
 log local0. "URI is [HTTP::uri]" 
 pool pool_apologies_http 
 log local0. "Directed to pool [LB::server pool]" 
   } 
 

Rev 2, tied the HTTP::uri command

 
 when LB_FAILED { 
 log local0. "URI is [HTTP::uri]" 
 log local0. "$poolname has [active_members [LB::server pool]] members" 
  HTTP::uri "/" 
 log local0. "URI is [HTTP::uri]" 
 pool pool_apologies_http 
 log local0. "Directed to pool [LB::server pool]" 
   } 
 

Can I do this with the 'when LB_FAILED' command, or does it have to be HTTP_REQUEST??

Thanks,

-L