Android Question Replace characters between two characters in a text file.

Dim TextWriter1 As TextWriter
    TextWriter1.Initialize(File.OpenOutput(File.DirRootExternal, "Log.dat",True))
   
    Dim ListCount As Int
    Dim ListCount1 As Int
    Dim ArtValue As String
    Dim Aantal As String
    ListCount = 0
    ListCount1 = 0
   
    Aantal = ListView2.GetItem(ListCount1)
    ArtValue = ListView1.GetItem(ListCount)
   
    Do While ListCount  < ListView1.Size
        ArtValue = ListView1.GetItem(ListCount)
        Aantal = ListView2.GetItem(ListCount1)
        TextWriter1.WriteLine(".2.|" & WonumText.Text.Replace("WO:","%")& "|000000.00"  & Chr(0) &   Chr(10) & Chr(13) & ".2.|" & ArtValue & "|" & "00000" & Aantal & ".00" & Chr(0))
        ListCount = ListCount + 1
        ListCount1 = ListCount1 + 1
        Log(".2.|" & WonumText.Text.Replace("WO:","%")& "|00000.00"  & Chr(0) &  CRLF & ".2.|" & ArtValue & "|" & "0000" & Aantal & ".00" & Chr(0)  & Chr(10) & Chr(13))
    Loop
    TextWriter1.Close

Sub replaceWithSpacesIfNeeded(searchIn As String,cr As String,delimiter As String,target As String,replacement As String) As String 
    
    '[searchIn]=original text
    '[cr]=character used as lines' separator
    '[delimiter]=character used as tabs' separator
    '[target]=string we want to replace by [replacement] string
    
    Private arr1() As String=Regex.Split(cr,searchIn)
    Private finalStringBuild As StringBuilder
    finalStringBuild.Initialize
    For i=0 To arr1.Length-1
        Private arr2() As String=Regex.Split(delimiter,arr1(i))
        For j=0 To arr2.Length-1
            Private startIndex As Int
            startIndex=arr2(j).IndexOf(target)
            If startIndex=0 Then 
                Private endIndex As Int=arr2(j).Length
                Private length As Int=endIndex-startIndex
                Private replacementLength As Int=replacement.Length
                Private finalReplacement As String=replacement
                If length>replacementLength Then 
                    For k=1 To length-replacementLength
                        finalReplacement=finalReplacement&" "
                    Next
                else if length<replacementLength Then 
                    finalReplacement=finalReplacement.SubString2(0,length)
                End If
                arr2(j)=finalReplacement
            End If
            finalStringBuild.Append(arr2(j))
            If j=arr2.Length-1 Then 
                finalStringBuild.Append(cr)
            Else 
                finalStringBuild.Append(delimiter)
            End If
        Next
    Next
    Private finalString As String=finalStringBuild.ToString
    Return finalString
    
End Sub

'replace this line:
'TextWriter1.WriteLine(".2.|" & WonumText.Text.Replace("WO:","%")& "|000000.00"  & Chr(0) &   Chr(10) & Chr(13) & ".2.|" & ArtValue & "|" & "00000" & Aantal & ".00" & Chr(0))

'with these four lines:
Dim LotsOfSpaces As String = "                    "    'at least 17 spaces

Dim TempDescription As String = (Aantal & LotsOfSpaces).SubString(0, 17)    'right-pad string to 17 characters long
Dim TempValue As String = NumberFormat2(ArtValue, 6, 2, 2, False)    'should format number as 000000.00

TextWriter1.WriteLine(".2.|" & TempDescription & "|" & TempValue & Chr(0))    'WriteLine should add on the CR LF

Sub Button1_Click
    Dim SepChar As String="\|"
    Dim myString As String=".1.|Hello world |00000" & CRLF & ".2.|Hi guys |00001"
    Dim arrS As List=Regex.Split(CRLF,myString)
    LogColor(myString,Colors.Yellow)
    For i=0 To arrS.Size-1
        Dim arrL As List=Regex.Split(SepChar,arrS.Get(i))
        arrL.set(1,"bye bye world")
        arrS.Set(i,Join(arrL,SepChar))
    Next
    myString=Join(arrS,CRLF)
    LogColor(myString,Colors.Cyan)
End Sub

Public Sub Join(lst As List, joinChar As Object) As String
 
    Dim retStr As StringBuilder
    retStr.Initialize
 
    For Each str In lst
        retStr.Append(str).Append(joinChar)
    Next
 
    Return retStr.ToString
 
End Sub