What you want is a SQL Server Agent Job, with a CmdExec step (which can execute a windows command line). This is explained here: http://msdn.microsoft.com/en-us/library/ms190264.aspx
If security is a concern, it can be secured through the use of a SQL Agent Proxy definition. This is explained here: http://msdn.microsoft.com/en-us/library/ms189064(SQL.105).aspx