Inform/Glulx Windows Question

A possibly-tricky question I’m hoping someone can help with:

I’d like to create a window, other than the main window, into which the user can enter text, so that play can switch between two windows at different points during a game.

I’ve had no problem setting up extra windows up using the Flexible Windows extension by Jon Ingold. The documentation for that extension also suggests that I can use hyperlinks in new windows using a statement that looks something like this:

To expect links in (g - a g-window): (--) glk_request_hyperlink_event({g}.ref_number); .
From looking through the Glk specification, it seems like it should be possible to specify that a window should “expect” text input in a similar way, maybe using glk_request_line_event() – but I don’t know my way around glk at all.

If anyone can help me with this, or even let me know if it’s possible, I’d be grateful.

Have you also had a look at the Gull documentation?

Also isn’t it Narcolepsy that implemented something like this?