Could someone assist with some advise on this curly question:

I need to 'compile' or assemble a composite 'sign'.

I need to place in a series of A3 files, into a 'giant' matrix.

Put another way, a single page approximately 6m long, ie. A3 'pages'
side by side on one 6m long canvas. In three rows, ie:

A3+A3+A3+A3 etc.. ]
A3+A3+A3+A3 etc.. ] on one page, 6m long.
A3+A3+A3+A3 etc.. ]

3 rows by however many to reach approx. 6m.

Is there a way I can write a script to compile this form me? The
document will be orginally created as A3 sheets in QuarkXPress, then
output as an EPS for us in Illustrator or other app. for compilation,
before being output as a PDF.

Does anyone now anyway I can script the compilation process, to join
the pages together, in Distiller, Illustrator, etc etc. Don't mind
how, just needs to happen.

Any thoughts?

Thanks
Ryan