Windows Background App to Modify Character Upon Keystroke

Place make .EXE file that when launched, it goes into bottom Windows taskbar. Purpose of it: When I type "=" after a certain letter (like "a"), it automatically changes "a" to Unicode: ā You can see 100% working replica of this at: [login to view URL] Type in "a", then right after, type "=". And you'll see it change to: ā That's exactly the behaviour that happens in Windows while .EXE file is running. Also some keys, when you for example press "m", followed by "=", it changes it to: ṃ But then when you press "=" the second time again, it'll change it to "ṁ". So here's the list of the keys to include: ===== a > ā d > ḍ h > ḥ i > ī l > ḷ > ḹ m > ṃ > ṁ n > ṇ > ṅ > ñ r > ṛ > ṝ s > ṣ > ś t > ṭ u > ū ===== Project should consist of 2 files: 1) [login to view URL] 2) [login to view URL] That way I can modify "[login to view URL]", should I need changes in future.