Masking my phone number

Hi, I am looking for someone who can help me with masking my phone number when I am sending messages to my clients. I know for systems where you can pay per lookup I am not interested in that. What I need is when I send SMS from my device the reciver need to see different number (Its can be my second number) or reciver can see my company name. I am doing bulk messaging to my clients, so it will be more effective if I can show my company name or another number. We are talking about Serbia. I will send messages from Serbia to Serbia.

I don't want any solutiong where I need to pay per message, so don't bid if you think of that.

If you know for any service for one time payment or monthy fixed price we can discust about that.