Here is an example. Adapt it to your needs...
function [] = gui_passdata()
% Pass data back and forth...
S.fh = figure('units','pixels',...
'position',[500 500 200 130],...
'menubar','none',...
'numbertitle','off',...
'name','gui_passdata',...
'resize','off');
S.ed = uicontrol('style','edit',...
'units','pix',...
'position',[10 60 180 60],...
'string','Enter Data, push button.');
S.pb = uicontrol('style','pushbutton',...
'units','pix',...
'position',[10 20 180 30],...
'string','Push to Get Data',...
'callback',{@pb_call,S});
guidata(S.fh,S);
uicontrol(S.ed)
function [] = pb_call(varargin)
% Callback for GUI_24 pushbutton.
S = guidata(gcbf); % Get the structure.
set(0,'userdata',S); % Save it in the root.
f = make_subgui;
% If user closes gui_passdata, close new one as well because it will
% error when it tries to execute the callback otherwise.
set(S.fh,'deletefcn',{@fig_delet,f})
function [] = fig_delet(varargin)
% Executes when user closes gui_passdata.
try
delete(varargin{3})
catch
% Do nothing.
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%SubGUI stuff...
function [f] = make_subgui()
f = figure('units','pixels',...
'menubar','none',...
'position',[750 510 200 100]); % Create a new GUI.
E = uicontrol('style','edit',...
'units','pixels',...
'position',[10 20 180 60],...
'string','Type something, press return.',...
'foregroundcolor','r',...
'callback',{@E_call});
pause(1.25)
S = get(0,'userdata');
str = get(S.ed,'string');
set(E,'string',str,'foregroundcolor','k')
uicontrol(E)
function [] = E_call(varargin)
% Callback for secondary GUI editbox.
S = get(0,'userdata');
set(S.ed,'string',get(gcbo,'string')) % Set gui_passdata editbox string.
close(gcbf) % Close SubGUI.
