Open file For Append

this vb6 code

                If Create_LoansArray(m_strClients(indx)) Then
                Open strSumFilename For Append As #15
                Print #15, "Successfully extracted data for client " & m_sClients(indx)
                Close #15

i need to convert to vb.net, how will the Open For Append part will be written in vb.net syntax?

thank you.