The id you have with the include tag is assigned to the root View of the included layout.
First get a reference to that View using findViewByid. Then you can call findViewById on that specific View to get a reference to a View inside the layout. So:
View myLayout = findViewById( R.id.cell1 ); // root View id from that link
View myView = myLayout.findViewById( R.id.someinnerview ); // id of a view contained in the included file