No. There isn't.
What you might want to do is perhaps run two DMX runs? Maybe one from a controller and one from MyDMX?
Or, perhaps say, you have a scene that is RED. Then you have another scene that is also RED but you have your strobes on, just ONCE(for example) or maybe you run them for a second or two. It's important. You'll see why in a moment.
So, you've got your red scene going and things are rocking and rolling, and you want to get that strobe in there. If you do a ZERO fade, nobody will notice the scene chance, and then you can have your strobes fire in Step 1, then off in step 2 that a whole second later and then the last step is of an indeterminate length. You can always re-invoke this scene as needed.
Seem maybe a little more along the lines of what you're looking for?
The answer is that while this CAN be done, it can't be done as you'd want it to be done. You're ALMOST trying to run one scene over the other(sort of) and MyDMX doesn't allow that.
While not perfect, it would give you the results you'd looking for. I'd also suggest that if you don't already have some sort of MIDI controller, you might want to consider something to make some triggering a bit easier for you, in addition to your keyboard. DOCUMENT!! and practice. And above all, have fun.