fop fo input file fop servlet

does anyone know if you can use a url as the fo input file path and name.
 
http://matt2/fop/fop?fo=c:/temp/test.fo
<http://matt2/fop/fop?fo=c:/temp/test.fo> 
 
this format works fine locally, but on the web the fo file would have to
reside on the clients computer
 
http://matt2/fop/fop?fo=//matt2/project3/test.fo
<http://matt2/fop/fop?fo=//matt2/project3/test.fo> 
 
does not work.
 
network name not found error.
 
does anyone knoe whether or not it is possible for the fo parameter to begin
with a www. or ip address or server name
 
i am running the servlet on tomcat 4.0 through iis 5.0 on a w2kp machine.