nawk, combine commands

How would I combine two nawk commands together without calling up nawk twice. Just like the sed -e command

nawk '$3>=from&&$3<=to' from="$STIME" to="$ETIME" | nawk '{$5="";$6=""}1'
nawk '$3>=from&&$3<=to {$5="";$6=""}1 ' from="$STIME" to="$ETIME" 

Thank you rdcwayx, this works perfectly!