MrShorty,

Thank you very much. A great solution to my problem! I didn't know tha
macros could be made into user defined functions. I'm sure I will b
using them again for other tasks.


SteveM,

Thank you for your interest in my question. I appreciate the time yo
have spent understanding the problem.

To answer your last question, "[what] prevents you from formulating i
on a worksheet", I need the use of 3-D look-up tables and to be able t
interpolate within the tables to obtain the coefficients I need. I a
also analysing around 5000 points (each requiring 2 look-up values
with three variables to be optimised and 30 or so equations to b
solved to obtain the target cell value) so a macro seems the mos
effective means to achieve this.


Jeff,

Thanks for the first response - keeping the thread alive.




wjm :

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