using VBA, how to remove the addidtional repeated characters at last - vba

Question

I have multiple rows, I need to join with "##" characters at end of every cell value,
I am able add this characters but at the end it is printing extra characters(##)
My excel file: From this excel file, I need to join the values by ## for each cell and feed into notepad
Excel File for Input
My output should be:(Actual and Expected)
Actual and Expected Output
Here Is my code:
sub join()
dim LRow as long
dim LCol as long
Dim str1 as string
Dim str2 as string
Dim ws1 As Worksheet
Set ws1 = ActiveWorkbook.Worksheets(1)
plik = ThisWorkbook.Path & "\" & "BL2ASIS" & ws1.Name & ".txt"
Open plik For Output As 2
With ws1
LRow = .Cells(.Rows.Count, 1).End(xlUp).Row
LCol = .Cells(1, .Columns.Count).End(xlToLeft).Column
LCol = LCol - 2
slast = vbNullString
str2 = Join(Application.Transpose(Application.Transpose(.Cells(n, "A").Resize(1, 2).Value)), "")
str1 = str2 & Join(Application.Transpose(Application.Transpose(.Cells(n, "C").Resize(1, LCol).Value)), "##") & "##"
str1 = Replace(str1, "=", vbNullString)
str1 = Replace(str1, "####", "##")
Print #2, str1
End with
end sub

Answer 1

You could replace your line:
str1 = Replace(str1, "####", "##")
with:
Do Until Len(str1) = Len(Replace(str1, "####", "##"))
str1 = Replace(str1, "####", "##")
Loop
which will keep applying the replace until there is no point in doing so (i.e. the length doesn't change)
EDIT
Sorry to alter an accepted answer, but I've noticed that you might want to keep instances of #### if they occur somewhere other than at the end of the row. If you do then the following would be better, as it only trims the right-most characters:
Do Until Right(str1, 4) <> "####"
str1 = Left(str1, Len(str1) - 2)
Loop

Answer 2

The reason you are getting repeated characters is because you are joining empty array elements. An alternative to removing repeated delimiters is to use a UDF to only join non null values. Please see below for such a function.
Sub TestJoin()
Dim r As Range: Set r = Worksheets("Sheet1").Range("B1:B12")
Dim arr() As Variant
arr = Application.Transpose(r)
Debug.Print NonNullJoin(arr, "#") & "#"
End Sub
Function NonNullJoin(SourceArray() As Variant, Optional Delimiter As String = " ") As String
On Error Resume Next
Dim i As Long: For i = 0 To UBound(SourceArray)
If CStr(SourceArray(i)) <> "" Then NonNullJoin = _
IIf(NonNullJoin <> "", NonNullJoin & Delimiter & CStr(SourceArray(i)), CStr(SourceArray(i)))
Next i
End Function

Answer 3

Use regex to replace more than one instance.
Note:
If you want to replace repeats only at the end of the string then change regex pattern to (##){2,}$ . This will deal with 2 or more occurrences.
If only worried about two occurrences at end, use (##)\1$
Code:
Option Explicit
Sub TEST()
Dim testString As String, pattern As String
testString = "xxxxx####"
testString = RemoveChars(testString)
Debug.Print testString
End Sub
Public Function RemoveChars(ByVal inputString As String) As String
Dim regex As Object, tempString As String
Set regex = CreateObject("VBScript.RegExp")
With regex
.Global = True
.MultiLine = True
.IgnoreCase = False
.pattern = "(##){2,}"
End With
If regex.TEST(inputString) Then
RemoveChars = regex.Replace(inputString, "##")
Else
RemoveChars = inputString
End If
End Function