Option Explicit

Private Const PAGE As Integer =  20 
Private mintPagedArray() As Integer
Private mlngPages As Long

Private Sub cmdLoadFirstPage_Click()
    PopulatePagedArray
    AddPage
    MSHFlexGrid1.RemoveItem  1 
    cmdLoadFirstPage.Enabled = False
End Sub

Private Sub cmdSearch_Click()
    MSHFlexGrid1.TopRow = CLng(txtSearch.Text)
End Sub

Private Sub MSHFlexGrid1_Scroll()
   If MSHFlexGrid1.RowIsVisible(mlngPages) = False Then
        PopulatePagedArray
        AddPage
   End If
End Sub

Private Sub AddPage()
    Dim i As Long
    
    If (mlngPages -  1 ) * (PAGE) <= MSHFlexGrid1.TopRow Then
        If mlngPages * PAGE < UBound(mintPagedArray) Then
            mlngPages = mlngPages +  1 
        
            For i = (mlngPages -  1 ) * PAGE To mlngPages * PAGE -  1 
                MSHFlexGrid1.AddItem vbTab & mintPagedArray(i)
            Next i
        End If
    End If
    
End Sub

Private Sub PopulatePagedArray()
    Dim i As Long
    
    ReDim Preserve mintPagedArray((mlngPages +  1 ) * PAGE)
    
    For i = mlngPages * PAGE +  1  To (mlngPages +  1 ) * PAGE
        mintPagedArray(i -  1 ) = i
    Next i
        
End Sub