Doubts about the rlm_replicate

Hi, I have a situation that I get a packet "Acct-Start" and then is necessary to duplicate and transform in a "Acct-Interim-Update". but, I should send the second packet "Acct-Interim-Update" after I get the "Accounting-Response" from the first sending "Acct-Start". have someone idea about the solution? My first thought was to add in rlm_replicate the capability to process a "preaccounting" and add some "flag" in the first packet saving in redis cache... but is a madness. I prefer to hear other suggestions! p.s: my radius is a proxy between two others. -- Jorge Pereira