How to Use Excel Functions in Access:

It would be very nice if I could call an excel function like yield directly
from a query.
Can this be done? If so, how?

Well, there are Excel functions and then there are Excel Add-ins (which
unfortunately includes Yield). The core worksheet functions can be included
as follows:

1. Open your database, type Ctrl+G to make sure you're in the VBA editor.
2. Choose Tools\References, and scroll down and check Microsoft Excel 10.0
Object Library (or whatever version of the Excel Object Library you have)
3. Use the functions as Excel.WorkSheetFunction.FunctionName, for example if
you type:
?Excel.WorksheetFunction.Ceiling(5,3)
in the immediate pane and hit enter, it should return 6.
4. To use such functions in queries, make a wrapper function by passing
appropriate data to the Excel function and returning the results, for
example:
Function MyCeiling(ByVal iOne As Double, ByVal iTwo As Double)
   MyCeiling = Excel.WorksheetFunction.Ceiling(iOne, iTwo)
End Function
5. Call that wrapper function from queries, as in:
   Result: MyCeiling([field1],[field2])

The Yield function, however, is a special case, as it's an Excel Add-in. If
you're *really* intent on using it, you can access it from automation, see:
http://support.microsoft.com/default.aspx?scid=kb;EN-GB;q198571

Probably best to develop your own library of functions: there are VB/VBA
versions out there for almost anything that you might need.

Originally posted by Max Dunn