Maybe this little macro would work for you:

Option Explicit
Sub testme()

Dim myProj As Object
Dim iCtr As Long
Dim myFileName As String

For iCtr = 1 To Application.VBE.VBProjects.Count
Set myProj = Application.VBE.VBProjects.Item(iCtr)
myFileName = ""
On Error Resume Next
myFileName = Dir(myProj.Filename)
On Error GoTo 0

If myFileName = "" Then
'unsaved project, do nothing
Else
Call TestFunction(myFileName)
End If

Next iCtr

End Sub
Sub TestFunction(wkbkName As String)
Dim res As Variant
Dim myStr As String

myStr = "yourfunctionnamehere(a1:a10)"
On Error Resume Next
res = Application.Run(wkbkName & "!" & myStr)

If Err.Number < 0 Then
'keep looking
Err.Clear
Else
MsgBox wkbkName & " Might be it!"
End If
On Error GoTo 0

End Sub

Change this line to match your function call:

myStr = "yourfunctionnamehere(a1:a10)"

============

Add another option to your Tools dropdown.
tools|customize|commands tab|tools category
Scroll down the commands side until you find: COM Add-ins...

Drag that to your favorite toolbar. I dragged it right under Addins under
Tools.

Then look to see if you have any COM Add-ins loaded.

wrote:

How do I find out what add-in a User Defined Funcion belongs to from
Excel when all the add-ins I have are loaded?

Unloading and loading the add-ins on by one to find out is to
timeconsuming for me. I have a number of xla and xll add-ins loaded.

Would also be nice if Excel 2003 COM add-in could be found.

Regards
Lars

--

Dave Peterson