substring and return the value after a specific character
you can use the split method to return the value after the colon :
Dim word as String = "Testing.BSMain, Text: Start Page"
Dim wordArr as String() = word.Split(":")
Dim result as String = wordArr(1);
Assumes no error checking:
Dim phrase As String = "Testing.BSMain, Text: Start Page".Split(":")(1)
which simply splits the phrase by the colon and returns the second part.
To use SubString, try this:
Dim test As String = "Testing.BSMain, Text: Start Page"
Dim phrase As String = test.Substring(test.IndexOf(":"c) + 1)