Title says it all.

We are migrating our tickets to freshdesk, and I am hoping there is some way to set the "references" and "in-reply-to" fields so that if customers reply to a migrated ticket it will be threaded correctly.

or any other ideas as to how to solve this.

To be specific lets say customer has a conversation going, and that conversation is now imported to freshdesk by our migration tool.

How can we get it so that future replies from that customer will be added to the conversation.   This is normally done by using the In-Reply-To and References meta tags, which I assume are stored someplace in the fresh desk database.