Hi Richard - welcome to the Forum.
The easiest way to solve your problem is to assign your string sound to Part5/Track 9 and then save this set-up together with your original set-ups in Panel memories. Then assuming your recorded sequence steps through the Panel Memories, the correct string sound will be selected, rather than the default piano sound.
I'm just down the road from you - Richmond in North Yorkshire so if you still have problems you can call me. I'll email you my phone number........
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Willum
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Willum
After silence, that which comes nearest to expressing the inexpressible is Music.
Aldous Huxley
( especially when the music is played on a KN7000....)