SMS Gateway (GOIP Modem)

[iknowyou]

I have a goip modem (Buy GoIP, voip adapter, GoIP4, DBL GoIP4 GSM VOIP Gateway 4GSM VOIP Voice Gateway Guaranteed 100% Brand New #RG0001 at Aliexpress.com), it already has the sim cards it needed. I'm connected to the device using the IP Address and entering username and password to access the modem configuration. Is there any here has an idea on how to create a SMS Server from a seperated Computer and the SMS server will schedule the sending of the messages. My problem now is that I can't send or command the Goip Modem to send a SMS using my VB.net application. Please help.