How to enter an xbar symbol (mean) in Procite?

I cannot find an x-bar symbol in Procite: the symbol denoting the statistic for the sample mean.

In other words, a lowercase x with a bar over it.

Does anyone know where this symbol is ? I looked through “Edit, Insert Symbol” but there are thousands of fonts in there. I tried to copy and paste the symbol from Microsoft Word (both 2007 and 2003) and from multiple websites. 

No luck. I am using Procite version 5.0

Thank you!