First, check HELP for the correct functions.
Generally, you could use EITHER the VB function OR the
Worksheet function, so check them both out.

1) Using the VB function
Function MyATAN(V1 As Double, V2 As Double) As Double
Dim first As Double
Application.Volatile
first = Tan(V1 / V2)
MyATAN = Cos(first)
End Function

2) Using the worksheet function
Function MyATAN(V1 As Double, V2 As Double) As Double
Dim first As Double
Application.Volatile
first = Application.WorksheetFunction.Atan2(V1, V2)
MyATAN = Application.WorksheetFunction.Cosh(first)
End Function


Patrick Molloy
Microsoft Excel MVP

-----Original Message-----
I have this formula in worksheet:

=COS(ATAN(E13/E14))

I want to create this formula in VBA but its not
available in the library.

I'm new to this VBA. I'll really appreciate if anybody
could help me out in this.

Thanks.

Sheela
.