Found a solution:
Use a blank simulink model. Copy/Past your "CAN-unpack" subsystem into it. Run the script.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% please mark the "CAN-unpack" before execution !
file=get_param(gcb,'CANdbFile'); % your CAN DBC file here!
db=canDatabase(file);
msg_name=get_param(gcb,'MsgName');
Msg=messageInfo(db,msg_name);
porthandles = get(gcbh,'PortHandles');
%%%% iterate thru all outports of the selected block and draw a signal line
for i = 1: size(porthandles.Outport,2)
%% draw a line at each Out-Port
pos = get(porthandles.Outport(i), 'Position');
linepos = [pos(1)+200 pos(2)-5 pos(1)+200+10 pos(2)+5];
temp_block = add_block('simulink/Commonly Used Blocks/Terminator',[gcs '/Term_' int2str(i)],'Position', linepos);
h1 = get_param(temp_block,'PortHandles');
add_line(gcs,porthandles.Outport(i),h1.Inport);
% get(porthandles.Outport(i)) % to see all properties
name =get(porthandles.Outport(i), 'PropagatedSignals');
linehandle = get(porthandles.Outport(i), 'Line');
set(linehandle, 'Name', name);
end
%%%% name all the signal lines according to outport-names
for i = 1: size(Msg.Signals,1)
linehandle = get(porthandles.Outport(i), 'Line');
set(linehandle, 'Name', Msg.Signals{i});
end