Please somebody!!

Having immense trouble with countif function. My situation is that I have a
range of values through time. I want to calculate the number of values below
the 95 percentile for those cells. I have used a formula of the form:
countif(C3:C263, "<percentile(C3:263, 0.95)") and tried removing speak-marks,
adding them in, tried calculating the percentile value in a seperate cell and
probably a lot more. Any ideas? Any help would be much appreciated.