MATLAB: Word manupulation

Question

i have 1 file in excel POS.xlsx contain word like this

A           B
hello      hi
enter     exit
me        you
love      hurt
what      how

when enter this word in edit text,my code working only for single wording let say i enter 'hello', it would show 'hi' when i enter 'hello me what' it wont show 'hi you how' what should i do to get that answer? below is my current code.

   txt1=get(handles.ayat,'string');
[num,txt]=xlsread('POS.xlsx');
for i=1:length(txt)
    txt2=txt{i,1};
      compare1=strcmp(txt1,txt2)
      if compare1 == 1 
          textOut=txt(i,2);
          set(handles.tag,'String',textOut);
          return;
      else
          promptMessage = sprintf('Maaf. Perkataan yang anda cari tidak terdapat dalam database');
          selectedButton = questdlg(promptMessage, 'Mesej','Cuba Perkataan Lain','Keluar', 'Cuba Perkataan Lain');
          if strcmp(selectedButton, 'Cuba Perkataan Lain')
              set(handles.ayat,'String','');
          return;
          end
          clear all;
          clc;
          close all;
          return;
      end 
end
for i=1:length(txt)
      txt2=txt{i,1};
      txt3=txt{i,2};
      t = strcat(txt1,txt3);
      if t == 1 
          textOut=txt(i,2);
          set(handles.tag,'String',textOut);
      end
  end

Answer 1

d ={'A'          'B'
'hello'      'hi'
'enter'     'exit'
'me'        'you'
'love'      'hurt'
'what'      'how'};
str1 = 'hello me what';
out = regexprep(str1,d(:,1),d(:,2));