You cannot get an application to run at logon that will elevate and somehow bypass the UAC dialog. That would pretty much defeat the purpose of UAC.
Your options include:
- Accepting that the user will be prompted for elevation.
- Modifying your application so that it does not require elevation. If some operations require elevation, then start a new elevated process to perform those tasks
- Running your process as service in session 0 where UAC does not apply.