Consuming a web service with authentication

I am involved in a project where I have to consume a web service....

I am very new to web services and have limited knowledge on this subject.
I desperately need help.
The web service provider has given us the following vb.net code , but I have no idea how to adapt it to work in LotusScript ....

Please can you assist me in any way.... Here is the code :

Try
            Dim sVendorCode, sApplicationKey As String

            sVendorCode = txtVendor.Text
            sApplicationKey = txtAppKey.Text

            Dim oHS As New Handshake.Handshake

            Dim oAS As New AddressService.AddressService
            oAS.Url = ConfigurationSettings.AppSettings("WSUrl")
            oHS.Url = oAS.GetURL("Handshake")

            txtVendorToken.Text = oHS.GetToken(sVendorCode, sApplicationKey)
        Catch ex As Exception
            txtOutput.Text = ex.Message.ToString()
        End Try

There is a second part where we login :
Try
            Dim sVendorCode, sApplicationKey As String

            Dim oHS As New Handshake.Handshake

            Dim oAS As New AddressService.AddressService
            oAS.Url = ConfigurationSettings.AppSettings("WSUrl")
            oHS.Url = oAS.GetURL("Handshake")

            Dim sLoginStatus, sMessage As String

            txtUserToken.Text = oHS.Login(txtVendor.Text, txtAccessKey.Text, txtAppKey.Text, sLoginStatus, sMessage)
            txtLoginStatus.Text = sLoginStatus

            txtOutput.Text = sMessage

        Catch ex As Exception
            txtOutput.Text = ex.Message.ToString()
        End Try