i have a spreadsheet with a macro that uses DAO to append data to an
Access database.

See code below:
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Sub ADOFromExcelToAccess()
' exports data from the active worksheet to a table in an Access
database
' this procedure must be edited before use
Dim cn As ADODB.Connection, rs As ADODB.Recordset, r As Long
' connect to the Access database
Set cn = New ADODB.Connection
cn.Open "Provider=Microsoft.Jet.OLEDB.4.0; " & _
"Data Source=P:\monthly200304.mdb;"
' open a recordset
Set rs = New ADODB.Recordset
rs.Open "Activity", cn, adOpenKeyset, adLockOptimistic, adCmdTable
' all records in a table
r = 1 ' the start row in the worksheet
Do While Len(Range("A" & r).Formula) 0
' repeat until first empty cell in column A
With rs
.AddNew ' create a new record
' add values to each field in the record
.Fields("ReportingMonth") = Range("A" & r).Value
.Fields("ReportingOrg") = Range("B" & r).Value
.Fields("SubOrg") = Range("C" & r).Value
.Fields("Speci") = Range("D" & r).Value
.Fields("LineID") = Range("E" & r).Value
.Fields("LineDescription") = Range("F" & r).Value
.Fields("Month") = Range("G" & r).Value
.Fields("Value") = Range("H" & r).Value
.Fields("CommProv") = Range("I" & r).Value
' add more fields if necessary...
.Update ' stores the new record
End With
r = r + 1 ' next row
Loop
rs.Close
Set rs = Nothing
cn.Close
Set cn = Nothing
End Sub
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Can anyone let me know if it is possible to add some code at the start
of the macro to look at the database and only export data from excel
to access if there is a certain value in the "ReportingMonth" field of
the database. (Basically to prevent duplicate additions to the
database).

Thanks,
Chris