...
m_ActnMenuObject = GetSubMenu(m_MainMenuObject,0); 
...

MENUITEMINFO lpmii;       
lpmii.cbSize = sizeof(MENUITEMINFO);
lpmii.fMask  = MIIM_TYPE|MIIM_STATE;
lpmii.fType  = MFT_STRING;
lpmii.fState = MFS_ENABLED;
lpmii.dwTypeData = "Свойства";
lpmii.cch        = (UINT) strlen( lpmii.dwTypeData );
SetMenuItemInfo(m_ActnMenuObject,0,TRUE,&lpmii);