one of the documented procedures in this installation of the ACS
ec_get_from_quasi_form   quasi_form   key
What it does:
CyberCash sometimes gives us a value back that is itself key/value pairs but in standard HTTP request form (e.g., "foo=5&bar=7"). We couldn't find an AOLserver API call that pulls this apart (though obviously the code is there somewhere, presumably in C).
Defined in: /web/philip/tcl/ecommerce-credit.tcl

Source code:

    if [regexp "$key=(\[^&\]*)" $quasi_form match the_value] {
	return $the_value
    } else {
	return ""