Cancel Button is not clickable when macro is running

[chooriang]

I create macros to find and replace texts in word documents. Consider the number of documents, I add a Cancel button to let the user to cancel the loop anytime. But the problem is, once the loop is started (start button is clicked) then Cancel button is then no longer clickable. How to keep the button clickable when macro is running?
Tried to google it but can't found solution.

Thanks.

 

[chooriang]

Maybe necessary to add the code

On Error GoTo errHandler
    With wsRaw
        lrRaw = Last(1, .Columns(1))
        lcRaw = Last(2, .Rows(3))
        
        For i = 4 To lrRaw
        
            If bCancel = True Then GoTo ExitSub
        
            strEmpName = .Cells(i, 2).Value
            
            Application.ScreenUpdating = True
            ws.Range("C13").Value = "Working on OT Form for """ & strEmpName & """"
            Application.ScreenUpdating = False
            DoEvents
            
            strOutputFile = addFileExtension(strTemplateFile, strEmpName)
            strOutputPath = strOutputLocation & strOutputFile
            FileCopy strTemplatePath, strOutputPath
            
            Set wdApp = GetObject(, "Word.application")    'gives error 429 if Word is not open
            If Err = 429 Then
                Set wdApp = CreateObject("Word.application")    'creates a Word application
                Err.Clear
            End If
            wdApp.Visible = False 'True '
            
            Set wdDoc = wdApp.Documents.Open(strOutputPath)
            'With wdDoc
            '    .Application.WindowState = 1
            '    .ActiveWindow.ActivePane.View.Zoom.Percentage = 100
            'End With
            
            For j = 1 To 7 'lcRaw
                strSearch = "< " & .Cells(3, j).Value & " >"
                strReplace = .Cells(i, j).Value
                For Each wdRng In wdDoc.StoryRanges
                    With wdRng.Find
                        .Text = strSearch
                        .Replacement.Text = strReplace
                        .Wrap = wdFindContinue
                        .Execute Replace:=wdReplaceAll
                    End With
                    DoEvents
                Next wdRng
                DoEvents
            Next  'lcRaw (data column)
            
            wdDoc.Close SaveChanges:=True
            Set wdRng = Nothing: Set wdDoc = Nothing
            DoEvents
        Next 'lrRaw (data row)
    End With