How to export the variable "http_proxy" when there are special characters in password?

Issue

• How to export the variable "http_proxy" when there are special characters in password?
• I am not able to export "http_proxy" variable when the password contains special characters, for example, password is "p@s#w:E"

# export http_proxy="http://username:p@s#w:E@server:port/"
# wget example.com
        --2011-03-15 03:30:51--  http://example.com/
        Resolving s... failed: Name or service not known.
        wget: unable to resolve host address “s”