Public Sub CenterC(frm As Form)
 
    Dim SpcF As Integer 'How many spaces can fit
    Dim clen As Integer 'caption length
    Dim oldc As String 'oldcaption
    Dim i As Integer
 
    oldc = frm.Caption
   
    Do While Left(oldc, 1) = Space(1)
        DoEvents
        oldc = Right(oldc, Len(oldc) - 1)
    Loop
 
    Do While Right(oldc, 1) = Space(1)
        DoEvents
        oldc = Left(oldc, Len(oldc) - 1)
    Loop
 
    clen = Len(oldc)
 
    If InStr(oldc, "!") <> 0 Then
        If InStr(oldc, " ") <> 0 Then
            clen = clen * 1.5
        Else
            clen = clen * 1.4
        End If
    Else
        If InStr(oldc, " ") <> 0 Then
            clen = clen * 1.4
         Else
            clen = clen * 1.3
        End If
    End If
 
  'see how many characters can fit
    SpcF = frm.Width / 61.2244 'how many space cam fit in the caption
    SpcF = SpcF - clen
 
    If SpcF > 1 Then
        DoEvents 'speed up the program
        frm.Caption = Space(Int(SpcF / 2)) + oldc
    Else 'if the form is too small for spaces
        frm.Caption = oldc
    End If
 
End Sub

Dim oldsize As Long
  
Private Sub Form_Resize()
    If Me.Width = oldsize Then 'if the width hasn't changed
        Exit Sub 'then don't change the caption location
    Else
        CenterC Me
        oldsize = Me.Width
    End If
End Sub
 
Private Sub Form_Load()
    CenterC Me
    oldsize = Me.Width
End Sub