obviously i can send sms via connecting my blue tooth device with my cell phone
Why would that be 'obvious'? Do *all* blue tooth cell phones support SMS from a PC over bluetooth? I don't think so. Just because a cell and a laptop both have bluetooth doesn't mean they can do *everything* together. Your bluetooth cell probably has a camera in it too: but I bet you can't fire it from laptop, or use it a laptop webcam.
You can only do what the manufacturers support in their firmware and API.
Write the cell phone maker for a SDK (Software Developer's Kit). If they tell you they don't provide one then you will have a hard time working out what features they do support, and don't. Not impossible, but hard.