conditioned functions

How do I set up a function that is conditioned by....
if any cell in column A equals a certain number than the C cell in that
particular row will equal a particular name?

John,

Starting with your first value in A then in C,

=IF(A1=Your Value,"Your Name","")

Copy this down your range. This will return a name if the condition is true and a blank cell if not true.

Cheers,

Steve