(acet-str-format "\nSpecify layer for new objects [Source/Current] <%1>: " def)
Under the express tools you can use acet-str-format and def (in this case) replaces %1. That's cooler than strcat and more like other languages.
I also think these ones could be pretty useful too.
(acet-sys-shift-down) ;call once to initialize
(acet-sys-control-down)
As long as you have express tools, you can call these functions. If anyone has rolled their own to remove themselves from the Express tools, that's cool too. Mind sharing the how?