parameterise timestamp in vugen

Using Loadrunner vugen 9.0, HTTP protocol, I am automating a web based App built on Java.
After log in, there is a HTTP request with query string parameter as follows that contains a timestamp. Fri May 14 15:53:13 UTC 0100 2010

web_url("Maintenance_2", "URL=xxxxxx/xxxxx May 14 15:53:13 UTC 0100 2010

Is there a way to substitute this with a function or parameter that will call the runtime timestamp ?