--- a/hook.c
+++ b/hook.c
@@ -42,6 +42,79 @@
 static HOOK *Hooks = NULL;
 
 static int current_hook_type = 0;
+static ENVELOPE *current_hook_env = NULL;
+
+int mutt_modify_header (BUFFER *buf, BUFFER *s, unsigned long data, BUFFER *err)
+{
+  size_t keylen;
+  char *p;
+  ADDRESS **c = NULL;
+
+
+  mutt_extract_token (buf, s, M_TOKEN_SPACE | M_TOKEN_QUOTE);
+  if ((p = strpbrk (buf->data, ": \t")) == NULL || *p != ':')
+  {
+    strfcpy (err->data, _("invalid header field"), err->dsize);
+    return (-1);
+  }
+
+  keylen = p - buf->data + 1;
+
+  if (current_hook_env == NULL) {
+	  strfcpy (err->data, _("not called inside a hook"), err->dsize);
+	  return (-1);
+  }
+
+  if (ascii_strncasecmp (buf->data, "reply-to:", 9) == 0) {
+	c = &(current_hook_env->reply_to);
+
+  } else {
+        strfcpy (err->data, _("can't handle this heaer"), err->dsize);
+	return -1;
+  }
+
+  switch(data) {
+  case MODIFYHEADER_ADD:
+	  /* FIXME: check if already there --tg 17:37 05-05-12 */
+	  *c = rfc822_parse_adrlist (*c, buf->data + keylen);
+	  break;
+
+  case MODIFYHEADER_CLR:
+	  rfc822_free_address (c);
+	  break;
+
+  case MODIFYHEADER_DEL:
+#if 0
+	  {
+		  ADDRESS *t = *c;
+		  while(t) {
+			  if (ascii_strncasecmp (buf->data + keylen, t->mailbox,
+					  mutt_strlen(buf->data + keylen)) == 0) {
+			  }
+			  
+			  rfc822_free_address (c);
+		  }
+	  }
+#else
+        strfcpy (err->data, _("not implemented"), err->dsize);
+	return -1;
+#endif
+	  break;
+
+  case MODIFYHEADER_SET:
+	  rfc822_free_address (c);
+	  *c = rfc822_parse_adrlist (*c, buf->data + keylen);
+	  break;
+
+  default:
+	  strfcpy (err->data, _("can only add, del or set header"), err->dsize);
+	  return -1;
+	  break;
+  }
+
+  memset (buf, 0, sizeof (BUFFER));
+  return 0;
+}
 
 int mutt_parse_hook (BUFFER *buf, BUFFER *s, unsigned long data, BUFFER *err)
 {
@@ -327,6 +400,7 @@
   char buf[STRING];
 
   current_hook_type = type;
+  current_hook_env  = hdr->env;
   
   err.data = buf;
   err.dsize = sizeof (buf);
@@ -344,11 +418,13 @@
 	  mutt_error ("%s", err.data);
 	  mutt_sleep (1);
 	  current_hook_type = 0;
+	  current_hook_env  = NULL;
 	  return;
 	}
   }
   FREE (&token.data);
   current_hook_type = 0;
+  current_hook_env  = NULL;
 }
 
 static int
--- a/init.h
+++ b/init.h
@@ -2920,6 +2920,7 @@
 };
 
 struct command_t Commands[] = {
+  { "add_header",       mutt_modify_header,     MODIFYHEADER_ADD },
   { "alternates",	parse_alternates,	0 },
   { "unalternates",	parse_unalternates,	0 },
 #ifdef USE_SOCKET
@@ -2930,10 +2931,12 @@
   { "alternative_order",	parse_list,	UL &AlternativeOrderList},
   { "bind",		mutt_parse_bind,	0 },
   { "charset-hook",	mutt_parse_hook,	M_CHARSETHOOK },
+  { "clr_header",       mutt_modify_header,     MODIFYHEADER_CLR },
 #ifdef HAVE_COLOR
   { "color",		mutt_parse_color,	0 },
   { "uncolor",		mutt_parse_uncolor,	0 },
 #endif
+  { "del_header",       mutt_modify_header,     MODIFYHEADER_DEL },
   { "exec",		mutt_parse_exec,	0 },
   { "fcc-hook",		mutt_parse_hook,	M_FCCHOOK },
   { "fcc-save-hook",	mutt_parse_hook,	M_FCCHOOK | M_SAVEHOOK },
@@ -2966,6 +2969,7 @@
   { "source",		parse_source,		0 },
   { "spam",		parse_spam_list,	M_SPAM },
   { "nospam",		parse_spam_list,	M_NOSPAM },
+  { "set_header",       mutt_modify_header,     MODIFYHEADER_SET },
   { "subscribe",	parse_subscribe,	0 },
   { "toggle",		parse_set,		M_SET_INV },
   { "unalias",		parse_unalias,		0 },
--- a/mutt.h
+++ b/mutt.h
@@ -319,6 +319,12 @@
 #define M_SPAM          1
 #define M_NOSPAM        2
 
+/* flags for mutt_modify_header */
+#define MODIFYHEADER_ADD (1<<0)
+#define MODIFYHEADER_CLR (1<<1)
+#define MODIFYHEADER_DEL (1<<2)
+#define MODIFYHEADER_SET (1<<3)
+
 /* boolean vars */
 enum
 {
--- a/protos.h
+++ b/protos.h
@@ -311,6 +311,7 @@
 int mutt_match_spam_list (const char *, SPAM_LIST *, char *, int);
 int mutt_messages_in_thread (CONTEXT *, HEADER *, int);
 int mutt_multi_choice (char *prompt, char *letters);
+int mutt_modify_header (BUFFER *buf, BUFFER *s, unsigned long data, BUFFER *err);
 int mutt_needs_mailcap (BODY *);
 int mutt_num_postponed (int);
 int mutt_parse_bind (BUFFER *, BUFFER *, unsigned long, BUFFER *);