The sensor is very small, so it requires a short focal length to cover it,
hence lots of DOF. Using the long end of the zoom will help, as will having
the background as far away as you can manage.
But generally, your standard lens is about 6 or 8mm., as against 50 for
35mm. tere's the problem. DSLRs have a somewhat bigger sensor so the problem
is less marked. But your sensor is not much bigger than a fingernail.

Basically, you are wasting your time trying.  Sorry!  

The small size of the sensor dictates that you will always get far
greater depth of field than with a larger sensor or 35mm film.  This
makes it extremely difficult to obtain a shallow depth of field with a
point and shoot digicam, even with a wide aperture such as f/2.8.

Your main option is to use a digital camera with a much larger sensor
such as a DSLR.  The shallowest depth of field will be obtained with a
DSLR using a "full size" sensor such as the Canon EOS 5D or 1Ds Mk II.
The APS-C size sensors in the Nikon, Pentax and Minolta/Sony DSLRs
will give greater depth of field, roughly equivalent to that obtained
with an aperture one f-stop smaller.  The Olympus, Panasonic and Leica
DSLRs using the smaller Four Thirds sensor give an even greater depth
of field, equivalent to an aperture two f-stops smaller.  

For example, for the same angle of view, using a lens at f/2 on any of
the Four Thirds DSLRs will give about the depth of field you would
expect at f/4 on 35mm film or a Canon EOS 5D.

The sensors in compact point and shoot digicams are tiny even compared
with the Four Thirds sensors, so there is enormous depth of field even
when using a relatively wide aperture such as f/2.8.

You're wasting your time.

You can fix it up in photoshop after, but you'll struggle to get it in
the camera with such a small sensor.