It's going to be best if you put all your reports directly into one window from the beginning. Creating a report and then moving it is difficult. Use the 'nw = New Window("container"); nw << Append(report);' format. For example:
//Get Example Data
dt = open("$Sample_Data\Big Class.jmp");
//Create Distribution report
dist = dt << Distribution( Continuous Distribution( Column( :height ) ) );
//deson't work b/c the display box is in another window
nw = new window("Example", dist);
nw2 = new window("Example2");
//Create the window directly in the container we want it to be in
nw2 << Append(dist = dt << Distribution( Continuous Distribution( Column( :height ) ) ););