urlencode msxml.domdocument for http request

niscox

Hi,
i have to send orders to an external application wich only accepts https requests with the (xml encoded) order as parameter.
e.g.:

https://www.external-application.de/bla-blub.cgi?new-order=<?xml ...

I used the msxml interface DOMDocument to build the xml document and interface XMLHTTP to send the request.
It's working as long as the xml document doesn't contain an ampersand.(but i guess other characters could cause similar problems)
Google told me to URLENCODE all parameters before posting.
So far msxml and mdac are required for the project.
The question is...
How to implement an urlencode method.
implement an urlencode method in navision or is there a usable method i overlooked in msxml or the mdac thing.