My 1999 VW polo 1.6i blows oil from the dipstick

Check the oil when the engine is cold. Make sure it's at the correct level.

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The Positive Crack Valve (PCV) is partial blocked.

This is under $10 item. You should change it.

The location of the PCV is on the top (or near top) of the valve cover.

Replace it and the oil/smoke will reciculate back to the correct path (back to the valve cover).

could be head gasket, but if motor is burning oil [smokey ] at the tail pipe then that would indicate piston rings!
as this is allowing combution into the engine block & pressurising it which acts like a pump & blows oil out from the weakest point [dipstick tube] or the valve cover breather, which ads more oil to the motor via the fuel intake!
either way its going to need a strip down & further inspection
I recommend a full rebuild or a replacement engine
Cheers & good luck Rob

sump is pressurising it will be ahead gasket ,if you are lucky cracked block if youare not but iwould think head gasket