I am pretty sure this is how its done... I can't test it tho as I am at work.
code:
<Control xsi:type="EditControl" Id="EdtTest">
<Attributes Align="Right">
<ReadOnly>True</ReadOnly>
</Attributes>
<DefaultText>Hello</DefaultText>
</Control>
or
code:
<Control xsi:type="EditControl" Id="EdtTest">
<Attributes>
<Align>Right</Align>
<ReadOnly>True</ReadOnly>
</Attributes>
<DefaultText>Hello</DefaultText>
</Control>