CREATION OF A CODE IN PHP TO BE ABLE TO SEND UNICODE MESSAGES

I need a coder to write a code that will check if sms messages contains Non-GSM characters and then convert the message to unicode before submission to my sms gateway. The challenge currently experienced is that when registered user on my sms website try to send a message written in other languages other than English,the message is not received on the recipient's phone as it was typed in the message box on my site. A code is also required for getting rid of duplicate mobile phone numbers when it is uploaded by a customer on their account.