xsd: any complex type?

[AL]

Hello,
working on an xsd schema, I'd like it to have a node of which I don't know
the content at design time: I want the document instance to identify such
node contents, where content should have a complex structure (complex type).
Probably xs:anytype is what I need, but I miss something...

In the following schema, I define a "genericchild" node, which I'd want to
be able to contain any (complex type) node I want to put in there:
:
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
elementFormDefault="qualified" attributeFormDefault="unqualified">
<xs:element name="myroot">
<xs:complexType>
<xs:sequence>
<xs:element name="genericchild" type="xs:anyType"/>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>

what I expect, is to build document instances like:

<myroot xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="C:\prova.xsd">
<genericchild><node1>string</node1></genericchild>
</myroot>

or

<myroot xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="C:\prova.xsd">
<genericchild><node2><a>atext</a><bb/></node2></genericchild>
</myroot>

Probably, such nodes (node1 & 2) should declare their namespace if I want to
validate, and/or should be declared as complex types, but the problem is I
get errors because "only text allowed inside element 'genericchild'".
Of course, the following validates well:

<myroot xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="C:\prova.xsd">
<genericchild>aa</genericchild>
</myroot>

Can anybody help?
thank you,
al.