one of the documented procedures in this installation of the ACS
dp_set_form_variables_after_query   { form_index "" }   { table_name "" }
What it does:
Copy variables from the ns_set $selection into the ns_set $dp_form with the proper naming conventions for the data pipeline. Caller must have $selection (just as for [set_variables_after_query])
Defined in: /web/philip/tcl/data-pipeline-defs.tcl

Source code:

    upvar selection selection
    upvar dp_form dp_form

    if {![info exists selection] || [empty_string_p $selection]} {
	return ""

    if {![info exists dp_form] || [empty_string_p dp_form]} {
	set dp_form [ns_set new]

    set form_size [ns_set size $selection]
    set form_ctr 0
    while {$form_ctr<$form_size} {
	ns_set put $dp_form "dp$form_index.$table_name.[ns_set key $selection $form_ctr]" [ns_set value $selection $form_ctr]
	incr form_ctr

    return $dp_form