having created 2 characters in PP is it possible to lock them together so that the could be moved around in the scene as if they were 1?

Load a sphere prop, hide it, and make the prop the parent of both characters  (Figure -> Set Figure Parent) - and then move the sphere prop.

You can actually parent one character to the other without creating the props.  Simply select the body part you want your second character to be parented to (i.e. Hip) and then move the first character to it's new location.

many thanks

Parenting on Person to another is a great way to do this if it is a single frame. But note if are wanting to use the people in an animation. This will cause problems where the body parts are parented to. Example:

I was making a Slow dance with a couple, I parented them at the hips to keep them close as they moved. The only problem with this is, if you move the legs . The person who is parented  to the other. their whole body bend with any hip movement you apply to that characture.

The good news was, I was able to use them from the waist up, they animate great above the hips. I used them as a couple moving in front of the main dance couple. But as for the main charactures, you need to bite the bullet and animate the dance moves. It's really not that hard to do, unless you want them to do something wild like the Tango. That will test your skills as an animator.