Here's the code from our tools. You just put it into Visual Basic part of Excel.
Global Const FNULL = -3.4E+38
Global Const DNULL = -3.4E+38
Global Const TRF = 459.67
Function third_cs#(ByVal Vis1#, ByVal TempF1#, ByVal Vis2#, ByVal TempF2#, ByVal TempF3#)
' ******************** THIRD_CS...