Have each button callback call the same function "WriteWorkbooks(handles)". In that function, it checks each checkbox and writes the data if it's checked
function WriteWorkbooks(handles)
checkbox1State = get(handles.checkbox1, 'Value');
checkbox2State = get(handles.checkbox2, 'Value');
checkbox3State = get(handles.checkbox3, 'Value');
if checkbox1State
% Write whatever data you want to for this checkbox.
xlswrite(.......
end
if checkbox2State
% Write whatever data you want to for this checkbox.
end
if checkbox3State
% Write whatever data you want to for this checkbox.
end
