SSRS ODBC (PostgreSQL) Parameter name

I am connecting to PostgreSQL from SSRS via ODBC. I have four parameters to pass and it looks like this.

From *
Select <tables>
where field1=? and field2=? and field3=? and field4=?

This creates four parameters with names Parameter1, Parameter2, Parameter3, Parameter4. In the datasource properties window I changed the names field1, field2, field3 and field4. This is not working. I even tried modifying the XML with no luck.

I need to change the names to the filed names as I want to call these parameters in the URL. How can I change the name Parameter1, Parameter2, Parameter3, Parameter4 to field1, field2, field3 and field4. I am not talking of the prompt but the actual name.