If by structurally you mean different bone counts, then yes retargetting is possible.
If you’re referring to the out by 90 or 270 degree bones to the right, I don’t know / never tried that.
If .bvh files, upon import you can specify the .bvh axis order which might fix the armature on the right. You can verify axis order via a text editor.
To save me repeating myself check out: Motion Capture in Blender