Thanks Chris. I have just made a simple test macro to demonstrate what I mean for upload... and in so doing have figured out the problem... it wasn't that the RegEx was failing to find the newline character, it was that my clipboard didn't have one! I had missed a "trim" statement earlier in the calling macro.
I should have heeded the advice from @jonathonl
... however I report here that my real cat is suitably unimpressed
Dave