In FE7 there is a specific AI command that tells Farina to talk to Hector. I've had to use this AI for FE4A and I figured I should post my notes on making things work for others just in case they want to use this feature.
First of all, without ASM hacking you can only do this once throughout your entire game. The AI command doesn't say "talk to the main lord" as some people have previously suggested. You must specify which character to talk to and which two characters the conversation is between.
0x06,0x0B,0x0A,0x00 is the AI we'll be using. Simply give the character you want to move and talk to another character this AI.
b97FE0: the ID of person the character will move toward.
1D3B54: The IDs of people who have the convo. First the initiator (character with the AI) and then the other character.
In FE4A I used this AI to have Alvis (7A) talk to Sigurd (03) in the prologue. At b97FE0 I wrote 03. At 1D3B54 I wrote 7A 03.
Special thanks to Nintenlord for his huge help with this. My notes are nearly 100% based off his findings.