What is exactly that you're trying to do? First of all, basically all objects have
ToString()[
^] method since it's defined on Object class and derived on all other classes.
If you're wondering what is the equivalent for variant, use object.
If the problem lies in conversion if varValue is Nothing, then you could use something like:
Public Function NullToText(varValue As Object) As String
If varValue Is Nothing Then
NullToText = ""
Else
NullToText = varValue.ToString()
End If
End Function
However, depending on your environment and what you use this function for, that may not work correctly if decimal numbers, dates etc. are passed to the function and different locales are used since the conversion should be culture aware. For example, see:
Int32.ToString Method (IFormatProvider)[
^]