Inheritance with Schemas

Hi all I am a newbie in XML and this list. Sorry in advance if this
question had been responded countless times before. (I just need a little of
direction).

I have the following problem. I have 2 XML schemas, one is some sort of
master document that defines a template for extension. 

<elementInTemplate1>
    <elementInTemplate2>
        <elementDefinedLater> ..{more info here}.. </elementDefinedLater>
    </elementInTemplate2>
    <elementInTemplate3>
        <elementDefinedLater2> ..{more info here}.. </elementDefinedLater2>
    </elementInTemplate3>
</elementInTemplate1>

Now I have created a complexType for <elementInTemplate2> named
elementInTemplate2Type that has a sequence from 0 to unbounded any elements.
Now I need to know how to define that I want to use elementDefinedLater in
elementInTemplate2 instead of elementDefinedLater2...

Or what would be the same, how can I left elementInTemplate2 open to
specialization while retaining validation without using xs:any elements.

Thanks you very much in advance

Federico Andres Lois
Software Developer
Bahia Blanca - Argentina