how to use exec command in C shell

i have a script where i am reading some lines from a file into another file..

script works fine in bash..

#!/usr/bin/csh
awk 'NR>20&&NR<32' try.sum | awk '{print $4 }' >io
awk 'NR>20&&NR<32' try.sum | awk '{print $9 }' >io1
awk 'NR>20&&NR<32' try.sum | awk '{print $14 }'>io2
exec 10<io
while (read LINE <&10)
ARRAY[$count]=$LINE
((count++))
end

how do i use the exec and read commands in c shell?

You don't, pretty much.

Read the first section 1.1a in this
Csh Programming Considered Harmful