How to reformat a matrix with a continuous string

Matrix A is as follows:

A = [7843,20,21,22,24,21;2345,21,23,22,24,25;5452,21,20,22,24,25;4231,20,21,22,23,20];

First convert 20 to A, 21 to B, 22 to C, 23 to D, 24 to E, 25 to F

I want matrix A to be formed like:

B = ['7843','ABCEB'
     '2345','BDCDE'
     '5452','BACDE'
     '4231','ABCDA'];

• I need this format for using in Align multiple sequences, link below:

http://www.mathworks.com/help/bioinfo/ref/multialign.html

Or like the following photo:

Answer 1

[dpb]

>> B=[cellstr(num2str(A(:,1))) cellstr(char(A(:,2:end)+'A'-20))]
B = 
  '7843'    'ABCEB'
  '2345'    'BDCEF'
  '5452'    'BACEF'
  '4231'    'ABCDA'
>>