How do you apply a 50 year moving Gaussian Filter to an ice core d18O record?

Firstly, apologies if this is the wrong group in which to raise this
question. I'm attempting to compile a number of proxy records for a
specific climatic event using ice core data and I need to apply a 50
year moving Gaussian Filter to reduce the noise. Can anyone shed some
light on how this is done in Excel, or OriginPro 8? I've tried to
follow the wikipedia advice but the 50 year moving parameter is really
throwing me. Many thanks.
.