Adam, not with a formula, but you can use a worksheet change event like
this, put in sheet code

Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Count 1 Then Exit Sub
If Target.Address = "$A$1" And UCase(Target.Value) = "Y" Then
'put your code here
End If
End Sub


--
Paul B
Always backup your data before trying something new
Please post any response to the newsgroups so others can benefit from it
Feedback on answers is always appreciated!
Using Excel 2002 & 2003

"Adam Kroger @hotmail.com" <adam_kroger<nospam wrote in message
. ..
Can you execute a macro from inside a formula?
IF(A1="Y",execute.macro,"")

Thanks