How to copy a single keyframe into another .blend file?

[DefraggedSSD]

I want to copy an idle position from 1 .blend file to another .blend file so i can animate from it and have all animations consistent. how can i do this?

[Mailer]

I am fairly sure you can copy a keyframe if you change the right column, or well any preferred viewport to, what I think is called "Animation Control?" where you should see, given that the model you are working on has an animation to begin with, a healthy length of diamonds. Every diamond would represent a keyframe, and you should be able to just copy a selected keyframe over with basic keyboard shortcuts.
As for pasting it again, I assume it would automatically set itself proper as long as the skeleton is the same.
I did similarly when I worked on animations for a set of doors, although I embedded both the open and close animation into the same model, which was kinda neat.
Because all I needed to do was reverse the animation to get the opposite, I just copied the keyframes over in reverse order.