There is no direct way to do this but, have a look at the following, it may help

VB Code:
  1. Option Explicit
  2.  
  3. ' to store the row/column of the cell
  4. ' being edited
  5. Dim m_lCellCol As Long
  6. Dim m_lCellRow As Long
  7.  
  8. Private Sub Form_Load()
  9.   m_lCellRow = -1
  10.   m_lCellCol = -1
  11.   txtCell.BorderStyle = 0
  12.   txtCell.Visible = False
  13.   ' set the text background color to the
  14.   ' backcolor of the tooltip text to make
  15.   ' the cell being edited having a different color
  16.   txtCell.BackColor = vbInfoBackground
  17.   MSFlexGrid1.Cols = 10
  18.   MSFlexGrid1.Rows = 10
  19. End Sub
  20.  
  21. Private Sub MSFlexGrid1_DblClick()
  22.   showTxtCell
  23. End Sub
  24.  
  25. Private Sub MSFlexGrid1_RowColChange()
  26.   removeTxtCell
  27. End Sub
  28.  
  29. Private Sub MSFlexGrid1_Scroll()
  30.   removeTxtCell
  31. End Sub
  32.  
  33. Private Sub MSFlexGrid1_SelChange()
  34.   removeTxtCell
  35. End Sub
  36.  
  37. Private Sub txtCell_Change()
  38.   MSFlexGrid1.Text = txtCell.Text
  39. End Sub
  40.  
  41. Private Sub showTxtCell()
  42.   If m_lCellRow = -1 Then
  43.     With MSFlexGrid1
  44.       ' store the current row and column
  45.       m_lCellRow = .Row
  46.       m_lCellCol = .Col
  47.       ' move the textbox to the correct cell
  48.       txtCell.Move .Left + .CellLeft, .Top + .CellTop, .CellWidth, .CellHeight
  49.       txtCell.Text = .Text
  50.       ' select all text
  51.       txtCell.SelLength = Len(.Text)
  52.     End With
  53.     txtCell.Visible = True
  54.     txtCell.SetFocus
  55.   End If
  56. End Sub
  57.  
  58. Private Sub removeTxtCell()
  59.   If m_lCellRow <> -1 Then
  60.     MSFlexGrid1.TextMatrix(m_lCellRow, m_lCellCol) = txtCell.Text
  61.     m_lCellRow = -1
  62.     m_lCellCol = -1
  63.     txtCell.Visible = False
  64.   End If
  65. End Sub
  66.  
  67. Private Sub txtCell_Validate(Cancel As Boolean)
  68.   removeTxtCell
  69. End Sub

For this you will need to add a Textbox control called: txtCell also

Not writtne by me...

Cheers,

RyanJ