The task of encoding non-printing characters by writing printing characters is typically solved by using special characters. In this case though, there no escaped/special characters to represent ASCII chars 2 and 3.
>> fmt = sprintf('%s%%s\\r\\nR,%%f,%%f\\r\\nL,%%f,%%f\\r\\n%s',2,3)
fmt =
%s\r\nR,%f,%f\r\nL,%f,%f\r\n
>> +fmt % checking
ans =
2 37 115 92 114 92 110 82 44 37 102 44 37 102 92 114 92 110 76 44 37 102 44 37 102 92 114 92 110 3
Although given the locations of those special characters, you could simply concatenate them onto the ends of the string:
fmt = [char(2),'%s\r\nR,%f,%f\r\nL,%f,%f\r\n',char(3)];
Note if you fopen the file using the t option, then it is not required to specify both \r and \n for each newline as this gets converted to a single newline:
fid = fopen(...,'rt'); % note the "t" !
out = textscan(fid,[char(2),'%s\nR,%f,%f\nL,%f,%f\n',char(3)]) % \r not required
fclose(fid)
This makes your code multi-platform and easier to write. I would highly recommend using the t option when reading text files.
