in the status bar
CEikStatusPane* sp=iEikonEnv->AppUiFactory()->StatusPane();
CAknContextPane* cp=(CAknContextPane *)sp->ControlL(TUid::Uid(EEikStatusPaneUidContext));
_LIT(KContextBitMapFile, "my_bitmap_file.mbm");
CFbsBitmap* bitmap = iEikonEnv->CreateBitmapL(KContextBitMapFile, EMbmBitmap);
CleanupStack::PushL(bitmap);
CFbsBitmap* bitmapmask = iEikonEnv->CreateBitmapL(KContextBitMapFile, EMbmBitmapMask);
CleanupStack::PushL(bitmapmask);
cp->SetPicture(bitmap, bitmapmask);
CleanupStack::Pop(); // bitmapmask
CleanupStack::Pop(); // bitmap
DrawNow();