How could I compute the balance from my column P(Debit) and Column Q(Credit) into column R(Balance).
I want use vba to do that (=P1-q1). If no data then just empty space. I have 1000 rows in that sheet.

I have 2 columns of data and 3rd column is a balance column.
And also want to lock the Balance column.


Data is like below

Debit Credit Balance(Result)
120 120 0
10 12 -2
        12 -12
30 30

.. ;; ;;
;; ;; ;;
Thanks in advance.....

Formula for C assuming your data starts in row 2 after headings:
=B2-A2
Populate this formula down.

To lock just B when the worksheet is locked:
1) Select all cells by clicking the button to the left of column A (Above row 1).
2) Click Format > Cells.
3) Click Protection Tab in the Format Cells menu.
4) Uncheck Locked.
5) Click OK.
6) Click C column button to select column C.
7) Click Format > Cells.
8) Click Protection Tab in the Format Cells menu if not already selected.
9) CHECK Locked.
10) Click OK.
11) Click Tools > Protection > Protect Sheet.
12) Make any additional permission choices.
13) Click OK.

Hope this helped point you in the right direction, but it really isn't a VBA question.

Not sure why you WANT to use VBA... but you can make the code something like this:

------------------------------------------------------------------------
Private Sub CommandButton1_Click()

  Dim oSheets As Worksheet
  Set oSheets = Worksheets("Sheet1")
  oSheets.Range("C2:C5").Value = "=IF(AND(A2="""",B2=""""),"""",A2-B2)" 'Whatever range you want to set.
  oSheets.Cells.Locked = False
  oSheets.Range("C:C").Locked = True
  oSheets.Protect

End Sub
------------------------------------------------------------------------

The above sample does it when a button is clicked.

Also the formula above would be:
=IF(AND(A2="",B2=""),"",A2-B2)
instead of just =A2-B2 since you want "" when there is no values in A or B.