Sned/REceive SMS through GSM Modem via PCMCIA

i am using vb6 to create the interface that would send and receive sms.  i already have a gsm modem but not like the ones most members of experts-exchange talk about.  my modem is connected to my laptop via pcmcia slot (DZ-800).  i am using AT-Commands to communicate with my gsm modem.  here's how the code in vb goes:

Private Sub cmdSendMesg_Click()
With mscomm1
 .CommPort = 5
 .InputLen = 0
 .Settings = "115200,N,8,1"
If Not .PortOpen Then
  .PortOpen = True
End If
 .Output = "AT" & Chr$(13) & Chr(10)
 .Output = "AT+CMGF=1" & Chr$(13) & Chr(10)
 .Output = "AT+CSCA=" & Chr$(34) & "+639189035759" & Chr(34) & _
 Chr$(13) & Chr(10)
 .Output = "AT+CMGS=" & Chr$(34) & txtRecpMobileNo & Chr(34) & Chr(10)
 .Output = txtMesg & Chr$(13) & Chr(26) & Chr$(13) & Chr(10)
 Dim dtToday As Date
 dtToday = Now()
 Do
 DoEvents
  buffer$ = buffer$ & .Input
 Loop Until InStr(buffer$, "OK") Or Now > DateAdd("s", 10, dtToday)
 If InStr(buffer$, "OK") Then
 MsgBox "Message Sent"
 Else
 MsgBox "Unable to send message"
 End If
 .PortOpen = False
 End With
 End Sub

if you would notice, my port number is set to 5.  this is because under control panel the port for my pcmcia card is set at 5.  

when i ran the program at port5, the invalid port number error appears.  when i tried to change to port 1, the msgbox would appear saying "unable to send message".  when i changed to port number 2, msgbox "message sent" would appear but actually there is no sms sent.  

i've been working on this code for 4 days now and to tell you guys honestly, i'm going cuckoo right now.  can anybody please help me.  pls tell what's wrong?? is the problem with the code or with the modem??  if so please specify solution. thanks you guys.