Loading text into the input buffer and displaying it as though the player typed it (Inform)

So apparently there’s a way to display text as though the player had typed it in, but not hit enter yet (so it can still be deleted with the backspace key). Zarf says this would involve pre-loading text into the input buffer, and using this line from VM_ReadKeyboard, with the number of characters substituted for 0:

glk_request_line_event(gg_mainwin, a_buffer+WORDSIZE, INPUT_BUFFER_LEN-WORDSIZE, 0);

Can anyone give me an example of how to do this? I don’t really know I6 at all but I’m guessing something along these lines:

To copy (T - a text) into the input buffer:
	???

To display fake keyboard input with (N - a number) characters:	
	(- glk_request_line_event(gg_mainwin, a_buffer+WORDSIZE, INPUT_BUFFER_LEN-WORDSIZE, {N}); -).     

Text-to-paste is some text that varies. Text-to-paste is usually "jump".

Last for processing hyperlinks:
	[other stuff]
	Copy text-to-paste into the input buffer;
	Let C be the number of characters in text-to-paste;
	display fake keyboard input with C characters.

Never mind; answered elsewhere!