The only help-file example of using @LINE on redirected standard input is
(echo %@line[con,0]) < myfile.dat
which does work.
However, the assumption is that, if myfile.dat is, forexample:
a
b
c
, then
(echo 0=%@line[con,0] 1=%@line[con,1] 2=%@line[con,2]) < myfile.dat
"should" echo
0=a 1=b...