dataflow advanced profiles export with custom decimal separator

Question

I need to change dot to comma on product price when I export using dataflown advanced profile. I tried this way:

...
<action type="dataflow/convert_parser_csv" method="parse">
     <var name="delimiter"><![CDATA[;]]></var>
     <var name="enclose"><![CDATA["]]></var>
     <var name="fieldnames">true</var>
     <var name="store"><![CDATA[0]]></var>

     <var name="decimal_separator"><![CDATA[,]]></var>

     <var name="adapter">catalog/convert_adapter_product</var>
     <var name="method">parse</var>
</action>
...

But this not work, how I can do this only for this profile? I'm trying to do this programming, copying from core to local, but without success.

Thank you!