[AccessD] Storing custom datatypes in collections

Has anyone ever succeeded in storing a custom data type in a collection?  I
get an error message:

"Compile error

Only user defined types defined in public object modules can be coerced to
or from a variant or passed to late bound functions."

This is the code I'm using:

Public Type TblDat
    strCnn As adodb.Connection
    strTblName As String
End Type

Public colTest As Collection

Public Function SVTblDat(lstrCnn As adodb.Connection, lstrTblName As String)
As TblDat
Dim lTblDat As TblDat
    Set lTblDat.strCnn = lstrCnn
    lTblDat.strTblName = lstrTblName
    SVTblDat = lTblDat
End Function

Public Function TestCollection()
    Set colTest = New Collection
    colTest.Add SVTblDat(CurrentProject.Connection, "1234")
End Function

Calling TestCollection and the error highlights SVTblDat(

Anyone?

John W. Colby
www.ColbyConsulting.com