I have version 2.9.27 /ip dhcp-server option add code=249 name="static-routes" value="0x080ac0a810fa10c0a8c0a810fa" - sets two static routes on Windows XP: 08 = mask /8, 0a = 10.0.0.0 (with mask /8), gateway c0a810fa = 192.168.16.250; and 10 = mask /16, c0a8 = 192.168.0.0 (/16), ...