At first must specify if want to use GSM or SMPP links?
If you want to use SMPP links, please contact one of the
VAS(=Value Addes Services) provisers, Magfa, Rahyab or
Atied Dadeh Pardaz. but if you want to use GSM, you must
enable your PC with GSM Modem. About sample  code,
just google this. I hope you will find a lot!