I have done a search but have been unable to find an answer for this question.

I have a LONE4 starting in Sep, with the first 2 flights dated, the rest left open, issued by AA. Is it possible to do the following:

LHR-NRT (dated)
NRT-HKG (dated)
HKG-BKK (leave open)
SIN-DRW (leave open)
MEL-CNS (date this one)

i.e date a ticket ahead of others that are left open-dated?

Thanks