Hate to be in the basic learning process, but have to start somewhere 
I sort of understand what you say, but still got some questions to your answer:
VB string to split the string; does that mean that VB will split the string after a specific "letter"?
Alternatively make it easier .. .. (can i program the arduino to send 2 seperate reading?
If you don't mind, please copy my codes and put in the examples 
Something like this?
' String to search in.
Dim searchString As String = "XXpXXpXXPXXP"
' Search for "P".
Dim searchChar As String = "P"
Dim testPos As Integer
' A textual comparison starting at position 4. Returns 6.
testPos = InStr(4, searchString, searchChar, CompareMethod.Text)
' A binary comparison starting at position 1. Returns 9.
testPos = InStr(1, SearchString, SearchChar, CompareMethod.Binary)
' If Option Compare is not set, or set to Binary, return 9.
' If Option Compare is set to Text, returns 3.
testPos = InStr(searchString, searchChar)
' Returns 0.
testPos = InStr(1, searchString, "W")
And where do I put the string code, what other changes do i hve to do with the code to define the different strings? (If that's the case) ...
Or something like this with the arduino?
Serial.print('<'); // start marker
Serial.print(value1);
Serial.print(','); // comma separator
Serial.print(value2);
Serial.println('>'); // end marker