deserialization problem

[Alex]

i have kind of an urgent problem with a deserialization.
i have all the clasesses generated by xsd.exe from the xsd file.
the xml i get and ai have to deserialize is seomthing like this:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<m:incomingEngineMessage xmlns:c="http://www.bvb.ro/xml/ns/arena/gw/
constraints" xmlns:m="http://www.bvb.ro/xml/ns/arena/gw/msg"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<content xsi:type=...>
...
</content>
<csq>10003</csq>
<err>false</err>
<id>213</id>
<kmsg>to ADMIN: Hello</kmsg>
<ktime>20070827174849441</ktime>
</m:incomingEngineMessage>

the <contentis defined in classes as type object. it is a different
type of object each time. once is some class , other time is some
other class.
when i deserialize everything works great, but the <content>,i get a
XmlNode[] in that field wich contains the XmlNodes that are the
properties of the class i have to cast it. (maybe it should be like
that).

now... i don't have access to the server application, i only get the
xsd from wich i generate my classes, and "content" is of type object.
how do i get that object casted to my needed type of object?
(xsi:type = m:UserEnvDto for example, so i need to cast that content
of type XmlNode[] to UserEnvDto class)