regexprepfile(filename,exp,repstr) performs a regular expression replacement using the pattern exp in the file filename with the string repstr. exp, repstr may also be cell arrays of strings of the same size, in which case the replacement is performed for each pair by performing a regexprep using corresponding elements of the inputs. Alternatively repstr may be a string and exp a cell array, in this case the single string repstr will replace all the patterns in exp.
regexprepfile replaces the string by creating a temporary copy of the file in which the replace is to be performed, replacing it in this file, and copying the file back to the original location for safety.
Note regexprepfile requires 'samesize.m' my file exchange contribution here: http://www.mathworks.com/matlabcentral/fileexchange/36636-samesize