controlling positioning device

hello all
i am working with some positioning devices and need to control them using visual basic.
the devices need some configuration strings (which are text files stored in the computer) to start them working.
i have the software which ships along with the devices but it isnt very user friendly and hence my employers wanted to have a visual basic code instead to do the job. the software interface has some 4-5 buttons which says open (sends the text file to the device register), search( searches how many devices are connected over the serial port), go (the device starts working and display their output).
i was trying to use mscomm but i had little success to send the text strings as well as retrieve any data.
can anyone of u plz tell me what to do or guide me someway.
any sample code would be of great help.
regards. shefali.

Not sure what you ask for, but is this http://www.devx.com/vb2themax/Tip/18344 a start?
Or in VB2005: http://www.devx.com/dotnet/Article/31001/0

How is this device connected to the computer?
Do you have an SDK for it?
Is it's driver or control-protocol documented?
Have you asked the vendor or manufacturer for help?

thanks both of u for ur replies. ember i have gone thru the links u have given. they werent much of an help to me.
the device is connected thru serial port (rs232).
http://www.hexamite.com/hx9.htm
hx900 is what i m using. i have asked for help from the vendor, but havent got any.
any help will be invaluable to me.
thanks again.

please someone help me with this. i am stuck and desperately need some help.
the device needs some text files for them to work.
when the device first recieves the text file it responds accordingly. and then the next text file has to be send and so on.
but when i use the following code i dont get back anything from the device.
how do i send data which is stored in a textfile to the device?
plz help people.

VB Code:

Private Sub Command1_Click()
      MSComm1.Output = Text1.Text
 
End Sub
 
Private Sub Command2_Click()
 
    Text2.Text = MSComm1.Input
    
End Sub
 
Private Sub Form_Load()
    With MSComm1
        .CommPort = 1
        .Settings = "19200,N,8,1"
        .InputLen = 0
        .RThreshold = 1
        .PortOpen = True
        
    End With
    
End Sub
 
Private Sub Form_Unload(Cancel As Integer)
    MSComm1.PortOpen = False
End Sub

I have been looking trough some earlier work and examples. Found one attached.