How to access pmid replies in private_insertpm_complete hook location?

[Majidm]

I'm working on a plugin that hooks into private_insertpm_complete

I'm having a really difficult time finding the proper pmid variable in replies

$pmdm->info['parentpmid'] works for the initial message, but I can't use this for replies because the replies have a different pmid

I've tried the following:
$vbulletin->input->clean_gpc('r', 'pmid', TYPE_UINT)
$pmdm->info['replypmid']
$pm['pmid']
$pm[pmid]

Anyone know how to access the pmid for replies?