Thanks, yawor. I too have played with the shortcut hot-key approach, and your reference to Flirc GUI is exactly what I had been looking for to replace the "shouldn't be obsolete but is" Keyspan GUI. I too have had mixed results, basically with the Win10 shortcut hot-keys themselves. I found a very nice open source solution in AutoHotKey: https://www.autohotkey.com/download/ , which is much more powerful than needed, has a small timing footprint, and can be set up with a script in minutes using a clearly written installed Help facility.
Pinning a shortcut to the task bar in Win10 would be a solution, save for the fact that Win10 ignobly steals activation from the current window, breaking the protocol of an old VB6 application that necessitated my need for an IR launcher in the first place. BTW, I was able to use Visual Studio 2008 Express (the free one) to migrate the VB6 project to VB.NET (64 bit) without much trouble. VS 2008 was the last to carry the VB6 migration tool, I found advice that suggested doing the VB6 migration to VS 2008, then, if really necessary, use VS 2017 Community (same as Express, new term for free) to migrate up from there.
I did see a reference to @jason 's future work with an Application Launcher in the Flirc PDF manual, which will eventually obviate the need for AutoHotKey. Meanwhile, your reference to assigning specific keyboard keys to a button on the remote has clarified a solution. I just now amazon'ed a Flirc. My remote is a Philips Universal, still being sold on amazon for around ten USD, and was what I had been using with Keyspan...until my dear old XP finally gave up the ghost a week or so ago. So I've been dragged into the new century with Win10 on a laptop. About time.