need some help with modifying excel in vb.net

can somebody please tell me how to modify my code so that it will open up an existing document in excel and modify that instead of creating a new one? my code looks like this right now


Module Module1

Sub Main()

Dim oExcel As Excel.Application
Dim oWorkbooks As Excel.Workbooks
Dim oSheets As Excel.Sheets ' <-- Quirk in XL requires Excel.Sheets
Dim oWB As Excel.Workbook
Dim oWS As Excel.Worksheet
Dim oRng1, oRng2 As Excel.Range

oExcel = New Excel.Application() ' <-- No 'Set' Keyword in .Net.
oExcel.Visible = True ' <-- Using .Visible = True is optional.

oWorkbooks = oExcel.Workbooks ' <-- oExcel.Workbooks.Add cannot be accessed in
oWB = oWorkbooks.Add ' in one line, or it will cause Excel to Hang.

oSheets = oWB.Worksheets ' < -- Again, oWB.Worksheets.Item("Sheets1") cannot
oWS = oSheets.Item(1) ' be accessed in one line.

oRng1 = oWS.Range("A1") ' <-- oWS.Range("A1").Value is to be avoided,
oRng1.Value = "Hello World!" ' for it would cause Excel to Hang.

oRng2 = oWS.Range("B2:E5") ' <-- oRng1.Copy(oWS.Range("B2:E5")) would again
oRng1.Copy(oRng2) ' hang the running instance of Excel.

Cleanup:
' Cleanup is more extensive for COM Automation than is typical for
' other areas of VB.Net. To be 100% certain that your Application
' and other related references are released properly, you should
' use a structure similar to the following:

NAR(oRng1) ' <-- See the Sub NAR(), below.
NAR(oRng2)
NAR(oWS)
NAR(oSheets)
NAR(oWorkbooks)

oWB.Close(SaveChanges:=True)
NAR(oWB)


oWB.Close(False)
NAR(oWB)

oExcel.Quit()
NAR(oExcel)
End Sub


Private Sub NAR(ByVal o As Object)
' This sub cleanly releases the COM Automation Object.
' Source: http://support.microsoft.com/?kbid=317109
Try
System.Runtime.InteropServices.Marshal.ReleaseComObject(o)
Catch
Finally
o = Nothing
End Try
End Sub


End Module


any help would be appreciated thank you.

Use Workbooks.Open instead of Workbooks.Add:'repalce this
oWB = oWorkbooks.Add
'with something like this
oWB = oWorkbooks.Open("c:\temp\test.xls")

Use Workbooks.Open instead of Workbooks.Add:'repalce this
oWB = oWorkbooks.Add
'with something like this
oWB = oWorkbooks.Open("c:\temp\test.xls")

thank you thats exactly what i needed