XML / XSLT Transformations with multiple files & tran

Hello all. I need some help with XSLT and understanding how I can
solve my problem. I have a set of 4 files, which are sampled below:

-- Job.xml--
<job id = "12"/>
<job id = "22"/>
<job id = "32"/>

-- Task.xml --
<task id ="1">
    <job ref = "12"/>
</task>
<task id ="2">
    <job ref = "22"/>
</task>
<task id ="3">
    <job ref = "32"/>
</task>

-- MyTasks.xml --
<mytask id = "1">
    <task-ref id="2"/>
    <task-ref id="3"/>
</mytask>
<mytask id = "2">
    <task-ref id="2"/>
    <task-ref id="3"/>
</mytask>

-- Configuration.xml --
<conf>
    <mytask-ref id = "1"/>
    <mytask-ref id = "2"/>
</conf>


The ref tags indicate the ids of the elements to use in the appropriate
files.
Here is what I wish my output to look like:

<conf>
    <mytask id = "1">

        <task id ="2">
            <job id = "22"/>
        </task>
        <task id ="3">
            <job id= "32"/>
        </task>

    </mytask>

    <mytask id = "2">

        <task id ="2">
            <job id = "22"/>
        </task>
        <task id ="3">
            <job id= "32"/>
        </task>

    </mytask>

</conf>

============ END OUT =================
Can anyone give me any pointers on how to acheive this ?

Any help would be very appreciated.

Regards,

Zak Nixon
XSLT newbie