Using .NET To Call COM Interface?

I need to call a function that takes an array of drive letters as one of its arguments. The sample I received from the dev team that created the object uses VBScript and looks like this:

Array("C:","D:")

This doesn't work in VB.NET so I tried the following code. Note: The drives are passed to me in a comma separated string:

Dim drives As String = "C,D"
Dim volumeList As String() = drives.Split(","c)
For i As Integer = 0 To volumeList.Length - 1
volumeList(i) &= ":"
Next

Then I try to pass volumeList to the function in question and I get an invalid argument exception. Is there some other way I could try to create/pass this array so that it acts like the VBScript example?