RewriteEngine On

RewriteCond %{DOCUMENT_ROOT}/root%{REQUEST_URI} -f
RewriteRule ^(.*)$ /root/$1 [L]

RewriteCond %{REQUEST_URI} !^/root/
RewriteCond %{REQUEST_URI} !^/?script/testapp_fastcgi.pl
RewriteRule ^(.*)$ script/testapp_fastcgi.pl/$1 [L]