If you are trying to write the cell array data to an MS Word file, then you should check out http://www.mathworks.com/matlabcentral/fileexchange/9112-writetowordfrommatlab in the MATLAB File Exchange for details on how to do this.
If you wish to simply write the data to a text file without loss of precision, then try something like
if fileID>0
for k=1:size(cellArray,1)
for m=1:size(cellArray,2)
% get the data type of the element in the cell array
dataType = class(cellArray{k,m});
% element data type determines how we write it to file
if strcmpi(dataType,'char')
fprintf(fileID,'%s\t',cellArray{k,m});
elseif strcmpi(dataType,'double')
fprintf(fileID,'%.10f\t',cellArray{k,m});
% etc. for each data type in the cell array
end
end
fprintf(fileID,'\n');
end
fclose(fileID);
end
By using the %.10f we are requesting that ten digits beyond the decimal place be written to file.