You can actually make the existing Formula work within Access.
Sin() and
Cos() are supported whereas
ACos() is
not, but you can execute this Function within Access using Automation Code. The following Code will work, assuming you substitute Values for the actual Variables, of course.
 'Make sure to 1st set a Reference to the Microsoft Excel XX.X Object Library

Dim objExcel As Excel.Application


Set objExcel = CreateObject("Excel.Application")


With objExcel.Application.WorksheetFunction

dist = .Acos(Sin(lat1) * Sin(lat2) + Cos(lat1) * Cos(lat2) * Cos(long3  long1)) * 6371

End With


MsgBox dist


objExcel.Quit

Set objExcel = Nothing