How to encode an mp4 to the exact specs of another mp4 with FFMPEG

Question

I'm working on a batch file to concatenate 3 files together, as follows:

1_Intro_Bumper.mp4,
2_Session.mp4,
3_Outro_Bumper.mp4

I've run into problems with the session.mp4 having slightly different specs, causing the concat to have weird problems with speed/sync/etc, and found out that if I encode the Bumpers through Handbrake to the exact specs of the Session, then the concat works great.

My question is: Can I bypass Handbrake here and include a line in my batch file to encode the Intro and Outro Bumpers to the exact specs of the Session?

Here's my current batch file:

:: Create File List

for %%i in (*.mp4) do echo file '%%i'>> mylist.txt

:: Concatenate Files

ffmpeg -f concat -safe 0 -i mylist.txt -c copy output.mp4

:: Encode to x264

ffmpeg -i output.mp4 output_x264.mp4

Thanks!