$ grep -i cps config.cfg | grep -v "//cps" | grep -v "cps := 4.1" |
    grep -v "cps := 2.2" | grep -v "cps := 5.1" | grep -v "cps := 7.4"|
    awk '{ SUM += $3} END { print SUM}'

set cpscmd1 "grep -i cps traffic.cfg"
set cpscmd2 "| grep -v "//cps" | grep -v "cps := 4.1" | grep -v "cps := 2.2"
set cpscmd3 "| grep -v "cps := 5.1" | grep -v "cps := 7.4"|
    awk '{ SUM += $3} END { print SUM}''"
...

exp_send "$cpscmd1 $cpscmd2 $cpscmd3 ";exp_sendr