Hi,
First of all, thanks to the many helpful folks here at blenderartists. You have always been there for me 
I have imported a model with rigging from another program, adjusted the rig in the blender, and then imported a walking bvh file. I then painstakingly set up bone constraints on the adjusted rig until I got a walk animation that looks good when playing it with the bvh import still in the scene, using those bone constraints. Now, I want to use those motions to automatically generate keyframes for the model. Basically, I want to record an animation on the rig I adjusted using the constraints I set up. I then want to delete the bvh file from the scene. In short this is an attempt to use a bvh motion capture file as a template for an animation. This is probably really simple, but my head is getting mushy from banging it on my desk.
I have tried copying the bvh rig keyframes in the dopesheet, switching to my adjusted rig, and pasting them. No luck – the paste icon is grayed out. So I try the same thing in the action editor, but first got a “no f-curves to paste into” even though I have selected all the channels. I next tried generating keyframes for a t-pose, then copying the keyframes in the dopesheet. The frames appeared on the dopesheet, but the timeline doesn’t show them and the rig doesn’t move.
Before anyone asks, I cannot post the blend file. I hope you’ll understand. Some direction on what sorts of things to look at would be very beneficial and appreciated. You might also sing out if there is another approach to this task that I am not trying.
Again, many thanks to all of you!