Code for SIM unlock HTC Desire 601

Hello everyone, I searched forum but couldnt find any thread about unlocking HTC Desire 601, I need sim unlock so I can put different SIM card, so would be happy if you could help me.

Model : HTC Desire 601
IMEI : 357985050220525
Network : VIP Mobile (Serbia)

Thanks once again, my previous thread was deleted, dont know reason, so If Im doing something wrong would be glad if administrator can annonuce me what Im doing wrong. 🙂