Hey JMB,
you are the man, but boy you must be getting sick of this!

What is happening now is when I test the compiling doesn't quite "interleave" properly. It seems to copy and position the specified cells correctly from the first sheet, but when it finds P5 and then goes to the next sheet it doesnt seem to copy exactly what is specified in that next sheet's P3 and P4. It seems to copy a few cells earlier, the required cells and a few later ones ie on the next sheet it copies cells within the matrix in additiona to what is specified in P3, P4.
I prob didnt say but for the reproduced matrix, it will be always made up of either 320 cells (or 160), there will be no gaps throughout the matrix i.e. the where P4 ends on one sheet P3 will start on the subsequent sheet so that there is continuous interleaving from one sheet to the next of the partial or whole octets of data, which in turn comprise the compiled 40 octet frame of data

Would it be easier to go to each sheet and copy the compiler to just make one 320 cell column (from 8 columns and 40 rows from parts of the various sheets) then change that column into a matrix??

Don't stress about it, I will figure something out.

I think that when I am testing that occasionally the compiler matrix does work properly when I specific certain combos of P3,P4 but will get to the bottom of this in the morning

Thanks for all your help you have been awesome

Best Regards

Simon