VS 2010 - Retrieving Item From Array

I have a function that is suppost to take a list of strings then split up each part. This is my code
For i As Integer = 1 To UPdata.Count
If InStr(UPdata(i), "!!") Then
Dim DataTBP() As String
Do
DataTBP = UPdata(i).Split("!!")
[Code] .....

One section of UPdata would look something like
ABC#DEF@GHIHSJD!!143#ISJ@PSIODH!!
What I want it to do is firstly separate the lines using !! so i would be left with
ABC#DEF@GHIHSJD
143#ISJ@PSIODH
That part works fine and I am left with an array DataTBP() with 2 values. The strings found above. Its then suppose to extract the part before # for every string left in DataTBP (In my example two) but the function that's meant to do this:

For j As Integer = 0 To UBound(DataTBP)
Dim DataType As String = DataTBP(j)
DataType = DataType.Split("#")
Select Case DataTBP(j)
[Code] .....

Throws me the error
Value of type '1-dimensional array of String' cannot be converted to 'String'.
But I don't know why as DataTBP(j) is a string not an array but a string. I've also tried
For Each a As String In DataTBP
Dim DataType As String = a.Split("#")
Next
It throws the same error