Thanks everyone. Glad I found this forum, been very helpful and can imagine it may be in the future.

It's a shame you can't combine but I guess that's the draw back of free flights then, suppose there has to be some restrictions.
I have been looking at various options, might just use them another time when I can get reward flights both ways if not, just though would be a good way to spend them on a long haul trip....

Thanks
Lewis