diff --git a/config/config.go b/config/config.go
index fbb531f7b..c7e302437 100644
--- a/config/config.go
+++ b/config/config.go
@@ -85,7 +85,7 @@ type CGRConfig struct {
 	BalancerEnabled          bool
 	SchedulerEnabled         bool
 	CDRSEnabled              bool          // Enable CDR Server service
-	CDRSExtraFields          []string      //Extra fields to store in CDRs
+	CDRSExtraFields          []string      // Extra fields to store in CDRs
 	CDRSMediator             string        // Address where to reach the Mediator. Empty for disabling mediation. <""|internal>
 	CdreCdrFormat            string        // Format of the exported CDRs. <csv>
 	CdreExtraFields          []string      // Extra fields list to add in exported CDRs
diff --git a/utils/consts.go b/utils/consts.go
index 61b66dd70..b543d47f8 100644
--- a/utils/consts.go
+++ b/utils/consts.go
@@ -64,6 +64,7 @@ const (
 	COMMENT_CHAR               = '#'
 	CSV_SEP                    = ','
 	FALLBACK_SEP               = ';'
+	REGEXP_SEP                 = '~'
 	JSON                       = "json"
 	MSGPACK                    = "msgpack"
 	CSV_LOAD                   = "CSVLOAD"
diff --git a/utils/coreutils.go b/utils/coreutils.go
index a4c78c212..6ac6b8cd6 100644
--- a/utils/coreutils.go
+++ b/utils/coreutils.go
@@ -225,3 +225,26 @@ func ParseZeroRatingSubject(rateSubj string) (time.Duration, error) {
 	durStr := rateSubj[len(ZERO_RATING_SUBJECT_PREFIX):]
 	return time.ParseDuration(durStr)
 }
+
+// Used to parse extra fields definition into regexp rules
+func ParseSearchReplaceRegexp(strRule string) (*regexp.Regexp, string, error) {
+	// String rule expected in the form ~hdr_name:s/match_rule/replace_rule/
+	getRuleRgxp := regexp.MustCompile(`:s\/(.+[^\\])\/(.+[^\\])\/`) // Make sure the separator / is not escaped in the rule
+	allMatches := getRuleRgxp.FindStringSubmatch(strRule)
+	if len(allMatches) != 3 { // Second and third groups are of interest to us
+		return nil, "", errors.New("Invalid Search&Replace rule.")
+	}
+	searchRegexp, err := regexp.Compile(allMatches[1])
+	if err != nil {
+		return nil, "", err
+	}
+	return searchRegexp, allMatches[2], nil
+}
+
+// Used to expand string sources, eg: extra fields
+func RegexpSearchReplace(src string, searchRl *regexp.Regexp, replaceTpl string) string {
+	res := []byte{}
+	match := searchRl.FindStringSubmatchIndex(src)
+	res = searchRl.ExpandString(res, replaceTpl, src, match)
+	return string(res)
+}