Hi,

I have a very large large spreadsheet (Excel 2003) with 20000 rows and
about 50 columns most with long complex formulas so calculation on
this sheet takes time. The main purpose of my code is to perform a
Goal Seek but depending on results the code might loop up to 100
times. Each Goal Seek takes about 9 minutes!

One column from the table changes at each iteration so what I want to
do is copy this column to another workbook, perform the Goal Seek,
then copy back my required result. My problem is though that if the
second workbook is in the same Excel instance as the actual table the
process is just as slow.

So my question is, how do I access a completely separate instance
(instance 2) within my VBA code so as to paste the 20000 line column,
perform the goal seek in that workbook then copy the result i require
back into instance 1

Any help appreciated

...pc