gistfile1.txt

In a script I build up a lit of filters that I want to apply to the output of a program.
This list may vary (tee, sort, uniq, ts, etc.) Could be all of them or none of them or any combination.
So I built up a list in a variable (_ql_append)

So _ql_append will have something like this in it:

"ilts -S -E | tee":
then the script executes this line:

( echo "$@"; "$@" ) | $_ql_append > "$_ql_filepath" 2>&1

But, the pipe synbols in _ql_append are treated as words, not as pipes:

+ cat '|' ilts -S -E '|' tee

so, if I want to build up an arbitrary piped set of filters, how should I 
do it? (the filters are all static strings in the program, not a security/rpbustness issue)