is it possible to get a valid response ?

I couldn't get either of these to work when I tested them. I've had great success adding to the URI, and would like to know how to specifically remove from it (without Chunking).:

when HTTP_REQUEST {
if { [HTTP::uri] starts_with "/b2b" } {
HTTP::path [string range [HTTP::path] 3 end]
}
}

or

when HTTP_REQUEST {
if { [HTTP::uri] starts_with "/b2b" } {
HTTP::path [string trimleft [HTTP::path] /b2b]
}
}

Any insight?