You need to add another ui object, probably text
or edit
beside the popup menu:
(I personally rather edit
since it looks nicer)
txt_obj = uicontrol(...
'Style','edit',...
'HorizontalAlignment','right',...
'String', 'Something',...
'Position' , [0,400,100,24],...
'BackgroundColor', [.9 .9 .9],...
'Enable','inactive');
I encourage you to use normalized units for ease of coding (positioning actually!). For more info see position property if uicontrol object and Positioning Figures (which has the same concept of positioning).