Excel 2008 : EXCEL - MED function

Hi, hope you can help me with a questions.

I have five number in five cells. I have to calculate the median of them like 3,5,6,8 and 10 and the result of this should be 6, right.

But sometimes on of those numbers are unknown and i just put (0) instead of it like 3,5,0,0,10 and the result is 3, right.

But the result should be 5 because 0,0 are not numbers in fact.

So, i need that the function MED (or other way) skip the 0 number.

Is that possible? Thank you much for your atention.