qgis - Python :ImportError: DLL load failed: The specified module could not be found

I am working on Python plugins for QGIS. I set my variables as

PATH :=C:\OSGeo4W\apps\qgis;%PATH% PYTHONPATH:=C:\OSGeo4W\apps\qgis\python

But when I try to run my .py file in IDLE I get an error saying:

Traceback (most recent call last):

File "C:\rt_sql_layer_working\DlgQueryBuilder.py", line 30, in from qgis.core import * ImportError: DLL load failed: The specified module could not be found.

What should I set for the PATH variable??