<message_body>
<pm:set_project_user_param id="MYPRIJECT">
<user_name>mikem</user_name>
<param datatype="i" name="TEST">value</param>
</pm:set_project_user_param>
</message_body>

A SetProjectUserParam message is sent by a client application or another cell service to add a user parameter to a specific project. The user and project needs to exist prior to calling this service. If the id attribute is specified, the record will be updated.
The domain, username, and password are sent in the header of the message so it does not need to be sent separately in the <message_body>.