LB help shows this text editor command.
print #handle, "!line n string$" ;
This returns the text at line n. n is standing in for a literal number.
But I have found that a variable can be used in place of n as long as you maintain the spaces, as in some other commands.
x$ = ""
#maint.teOneTbl, "!lines countVar" ;
for n = 1 to countVar
#maint.teOneTbl, "!line ";n;" txt1$";
if txt1$ = "" then exit for
x$ = x$ + txt1$ + " "
Not revolutionary, but interesting to me.