Looking for some help with how to use regular expression library I have a string "!1!" I am replacing it with "\temp\i\otrq92rq40100__db1003.xls" ( a windows path to a file) This is how I am doing it std::string repl=subst_designator+ boost::lexical_caststd::string(counter)+ subst_designator; boost::algorithm::replace_all_regex(new_arg, boost::regex(repl),*res_it); Where: subst_designator = '!' counter = 1 new_arg = "!1!" *res_it="\temp\i\otrq92rq40100__db1003.xls" after the above code, the new_arg contains a strange string that appears to have back slashes removed and the first \t replaced with something like a 'tab' new_arg=" empiotrq92rq40100__db1003.xls" I am thinking that this is wrong, because the regular expression should copy without modifications the value of *res_it into the new_arg I am using 1.38 on windows with VS9. My question is , how can make it so the string in *res_it substitutes !1! thank you in advance, Vlad -- Vlad P author of C++ ORM http://github.com/vladp/CppOrm/tree/master -- http://www.fastmail.fm - IMAP accessible web-mail