applied Hiltjo's patch as suggested on the ml to fix ControlMask for C-j and C-m - dmenu - my customized version of dmenu (hiltjo branch)
  HTML git clone git://git.codemadness.org/dmenu
   DIR Log
   DIR Files
   DIR Refs
   DIR README
   DIR LICENSE
       ---
   DIR commit 13a529ce63364544bdc851dfd5d3aa2ef8740914
   DIR parent aa69426670bf0ae480db127ff8d4fc62d6da2593
  HTML Author: Anselm R Garbe <garbeam@gmail.com>
       Date:   Wed, 17 Sep 2014 13:40:11 +0200
       
       applied Hiltjo's patch as suggested on the ml to fix ControlMask for C-j and C-m
       
       Diffstat:
         M dmenu.1                             |       3 +++
         M dmenu.c                             |       4 ++--
       
       2 files changed, 5 insertions(+), 2 deletions(-)
       ---
   DIR diff --git a/dmenu.1 b/dmenu.1
       @@ -136,6 +136,9 @@ Delete line right
        C\-m
        Return
        .TP
       +C\-M
       +Shift-Return
       +.TP
        C\-n
        Down
        .TP
   DIR diff --git a/dmenu.c b/dmenu.c
       @@ -256,9 +256,9 @@ keypress(XKeyEvent *ev) {
                        case XK_h: ksym = XK_BackSpace; break;
                        case XK_i: ksym = XK_Tab;       break;
                        case XK_j: /* fallthrough */
       -                case XK_J: ksym = XK_Return;    break;
       +                case XK_J: /* fallthrough */
                        case XK_m: /* fallthrough */
       -                case XK_M: ksym = XK_Return;    break;
       +                case XK_M: ksym = XK_Return; ev->state &= ~ControlMask; break;
                        case XK_n: ksym = XK_Down;      break;
                        case XK_p: ksym = XK_Up;        break;