Show a ProgressDialog and send an SMS in the background
What you are trying to achieve is such a common pattern (run some command in separate thread and then modify the UI with the result) that Android has a class just for that: AsyncTask.  There is also a small example in the dev guide and I'm sure all Android books must have a full section, if not a full chapter, about AsyncTask.

Be very careful about Java conventions.  When you don't respect them, the code is quite confusing for Java developers.  


Class names always start a capital letter, so CommandXDev instead of commandXDev.
commandXDev.Get.  I'm not quite sure what that is.  In Java, if you write a getter method, you always call it get followed by what you are getting, i.e. getName(), getId(), getSharedPreferences(), etc.  Your commandXDev.Get seems to be a static getter, which is best avoided.  I'm not sure what you are trying to do.  Maybe look into the singleton pattern.


Minor point: in English it is "sent" instead of "sended".  It does not make sense, but it is how it is.