Yes.
Add a bit attribute to the address element for that parameter.
Code:
<address bit="3">0xFF650D</address>
The bit is 0 base so you can use 0 - 7, where 7 is the most significant and 0 is least.
A complete example:
Code:
<ecuparam id="E2000" name="Switch bit 3" desc="E1403 [ 1 = On and 0 = Off ]" target="1">
<ecu id="0123456789">
<address bit="3">0xFF650D</address>
</ecu>
<conversions>
<conversion units="On/Off" expr="x" format="0" gauge_min="0" gauge_max="1" gauge_step="1" />
</conversions>
</ecuparam>