how do you want to use it on a report, is it in a text box, if so then set the textbox property ControlSource equal to "=MyFunction" and as long as the function is designed to return a string then this will work.
example of function in a basic module:
Code:
Public Function MyFunction() As String
dim strNewData as String
strNewData = "Test String from MyFunction"
MyFunction = strNewData
End Function
The .Texte (.Text) could be the problem as there is a difference between .Text and .Value and what you really want is the .Value which is the default if you don't reference it.
and because it's a report, try using the memory names instead of the control names like the following;