In the standard full A-Shell release, you will find a program ASHCAL.BAS in [7,376] which is pretty much exactly what you just described. Feel free to modify it as you like. There is also a pop-up menu program, ASHPOP, which can be configured as a menu of pop-up utilities. Note that if you pass the |P TYPE code combination to INFLD, hitting ^] will cause a child session to be launched running ASHPOP.
Search the User Guide for "ASHPOP" (as well as the UPDATE45.TXT) for further details.