Take specific string part of string by specific requirments - vb.net

Question

I am developing function which would give me the right side of specific string. Function has possibility to take the return string based on splitted char, keep char in string and also which is most important to say either return string will be after last occurence of that char separator or say after exactly which positon of separator occerence in string, return string after to take. Can anyone take a look on that and confirm is it right way to go or whether that code contains any issues?
Keep in mind to use as lastindex i set lastindexof to true and doesn't matter what splitterCharPosition is and vice versa when false splitterCharPosition has to be set.
This is my current code to be confirmed:
Public Function GetRightSideStringByCHar(splitterChar As String, searchingWord As String, keepCharAsWell As Boolean, lastindexof As Boolean, splitterCharPosition As Integer) As String
Dim index As Integer
Select Case lastindexof
Case False
index = GetNthIndex(searchingWord, splitterChar, splitterCharPosition)
Case True
index = searchingWord.LastIndexOf(splitterChar)
End Select
If index > 0 Then
If keepCharAsWell Then
searchingWord = searchingWord.Substring(0, index + splitterChar.Length)
Else
searchingWord = searchingWord.Substring(0, index)
End If
Else
searchingWord = String.Empty
End If
Return searchingWord
End Function
Helper function to get n index:
Public Function GetNthIndex(searchingWord As String, charseparator As Char, n As Integer) As Integer
Dim count As Integer = 0
For i As Integer = 0 To searchingWord.Length - 1
If searchingWord(i) = charseparator Then
count += 1
If count = n Then
Return i
End If
End If
Next
Return -1
End Function

Answer 1

Based on your other deleted question, I formulated this for you.
It worked with all your previous examples.
[parameters]
str = input string
strtofind = separator string
occurance = zero-based index to start cutting (optional)
keepstringtofind = append separator to string (optional)
righttoleft = operational direction (optional)
Public Function CutFromString(str As String, strtofind As String, Optional occurance As Integer = 0, Optional keepstrtofind As Boolean = False, Optional righttoleft As Boolean = False) As String
Dim s As String = str
Dim sections As List(Of String) = IIf(String.IsNullOrEmpty(str), New List(Of String), str.Split(strtofind.ToCharArray).ToList)
If sections.Count = 1 AndAlso sections.First = str Then sections.Clear()
If occurance < sections.Count Then
Dim b = sections.Count - occurance
While b > 0
If righttoleft Then
sections.RemoveAt(0)
Else
sections.RemoveAt(sections.Count - 1)
End If
b -= 1
End While
s = Join(sections.ToArray, strtofind)
If keepstrtofind And occurance > 0 Then
If righttoleft Then
s = strtofind + s
Else
s += strtofind
End If
End If
End If
Return s
End Function