Sub ConvertFormulasToTextForSheet()
  Dim ws As Worksheet
  Dim rng As Range
  Dim cell As Range
  Dim sheetName As String
 
  sheetName = "Sheet1" 
  Set ws = ThisWorkbook.Worksheets(sheetName)
  Set rng = ws.UsedRange
  For Each cell In rng
      cell.Value = "'" & cell.Formula
  Next cell
End Sub

Dim vals As Variant
vals = ws.UsedRange.Formula
If IsArray(vals) Then
    Dim i As Long, j As Long
    For i = LBound(vals, 1) to UBound(vals, 1)
        For j = LBound(vals, 2) to UBound(vals, 2)
            vals(i, j) = "'" & vals(i, j)
        Next
    Next
Else
    vals = "'" & vals
End If
ws.UsedRange.Value = vals

Sub SuspendFormula(Worksheet As Worksheet, Suspend As Boolean)
    Dim InitialCalculationState As XlCalculation
    Application.ScreenUpdating = False
    InitialCalculationState = Application.Calculation
    Application.Calculation = xlCalculationManual
        
    Dim Target As Range
    Set Target = Worksheet.UsedRange
    Dim Data As Variant
        
    If Target.Count = 1 Then
        ReDim Data(1 To 1, 1 To 1)
        Data(1, 1) = Target.Formula
    Else
        Data = Target.Formula
    End If
        
    Dim r As Long, c As Long
        
    For r = 1 To UBound(Data)
        For c = 1 To UBound(Data, 2)
            If Suspend Then
                If Left(Data(r, c), 1) = "=" Then Data(r, c) = "'" & Data(r, c)
            Else
                If Left(Data(r, c), 2) = "'=" Then Data(r, c) = Mid(Data(r, c), 2)
            End If
        Next
    Next
        
    Target.Formula = Data
    
    Application.Calculation = InitialCalculationState
End Sub