求助：关于改文件名

wgun

% --- Executes on button press in pushbutton9.
function pushbutton9_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton9 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

global gfile;
[filename3, pathname3, filterindex3] =uigetfile({'*.ts2;*.ts3;*.ts4;*.ts5';'*.ts2';'*.ts3';'*.ts4';'*.ts5'}, 'MultiSelect','on');
pathfile3=strcat(pathname3,filename3);
handles.pathfile3=pathfile3;
handles.filterindex3=filterindex3;
guidata(hObject, handles);
if iscell(handles.pathfile3)
[m,n]=size(handles.pathfile3);
for na=1:n
gfile=[gfile;cellstr(handles.pathfile3(1,na))];
end
else
  gfile=[gfile;cellstr(handles.pathfile3)];
end
assignin('base','gf',gfile);

prompt={'想加字符:'};
def={'a'};
dlgTitle='输入 字符';
lineNo=1;
zf=inputdlg(prompt,dlgTitle,lineNo,def);
assignin('base','zfs',zf);

[m1,n1]=size(gfile);
for m2=1:m1
    [mm,nn]=size(gfile{m2});
    newname = [gfile{m2}(1:nn-4),zf{1},gfile{m2}(nn-3:nn)];
    status = system(['rename'  ' ' gfile{m2}  ' ' newname]);
end

设计了一个按钮，现在选中的文件名后加一个a，比如：文件名为w.txt,变为wa.txt
前面都没错，就最后for循环里的改文件名的system有错，但不知道怎么改，请高手帮帮忙吧！！！