Help with formula or macro!

Hi,

I would suggest this code:

Sub SquareBracketsBeforeAndAfterTexts()
    'By Haytham Amairah
    
    On Error Resume Next
    Application.ScreenUpdating = False
    Application.EnableEvents = False
    Application.Calculation = xlCalculationManual
    
    Dim step1 As String
    Dim step2 As String
    Dim cell As Range
    
    For Each cell In Selection
        If cell.Interior.ColorIndex = -4142 Then
            step1 = Application.WorksheetFunction.Replace(cell, 1, 0, "[")
            step2 = Application.WorksheetFunction.Replace(step1, Len(step1) + 1, 0, "]")
            cell.Value = step2
        End If
    Next
    
    On Error GoTo 0
    Application.ScreenUpdating = True
    Application.EnableEvents = True
    Application.Calculation = xlCalculationAutomatic
    
End Sub

But you need to select the range of cells before you run this code.

Hope that helps