Some time ago, i found an example in VB on how to chage the names of the Buttons in a MsgBox. Many people want this functionality, so I converted it to AutoIt and here it is:
;### EXAMPLE
#include "CustomMsgBox.au3"
$REturn = xMsgBox(16+0x200,"Title","Text","Butt 1","The 2nd","The3rd",Default,34,"C:\vista.ico")
MsgBox(0, 'ReturnValue:', $REturn)CustomMsgBox.au3