VbScript code to add multiple values in Excel files

Option explicit
Dim oex, owb, nr, ows, a, b, eop, qop, i

'open excel sw
         Set oex=createobject("Excel.Application")
         oex.Visible=true 'set excel as visible
'open excel wb
       set owb=oex.Workbooks.Open("F:\Book1.xls")
'open excel worksheet
         Set ows=owb.Worksheets("Sheet2")

'count no of rows
         nr=ows.usedrange.rows.count 'count no of rows to be added

For i=2 to nr step 1
        a=ows.cells(i,1) 'get first input
         a=cint(a)
         b=ows.cells(i,2) 'get second input
         b=cint(b)
                eop=ows.cells(i,3) 'get value from excel
        qop=a+b 'add two inputs by using qtp
        print(qop)
        ows.cells(i,4)=qop 'store the ouput in qtp

      'check correct ness of addition
                 If eop=qop Then
         ows.cells(i,5)="Correct Value"
          Else
        ows.cells(i,5)="Incorrect Value"
         End If
Next

'save and close excel file
         owb.Save
        oex.Quit

'destroy object by de allocating the memory
         Set ows=nothing
         Set owb=nothing
         Set oex=nothing