RelativeLayout set custom View y

I am having a little trouble with this relative layout:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://ift.tt/nIICcg"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/background" >

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:text="@string/one_string" 
        android:onClick="goToScene2" />

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:text="@string/two_string" 
        android:onClick="goToScene1" />

    <Button
        android:id="@+id/button3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        android:text="@string/three_string" />

    <ImageView
        android:id="@+id/custView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:url="@drawable/panel_sets" />

</RelativeLayout>

wich renders the activity like this (scene2 in transition):

But i want to move ImageView like this image in order to later move it by aplying a transition in other layout.xml (this will be scene1). How can i do it?

Thank you very much