Spreadsheet Expiration After a Given Date - possible?

[bluesband]

Does anyone have suggestions for programming into a spreadsheet some
mechansim whereby the spreadsheet will stop functioning properly after a
given date?

I ask because I develop financial models for clients that I'd like to get a
royalty for every six months. Without some sort of mechanism built in to my
model, users could use it indefinitely, which is not to my desire.

Thoughts?

 

[Frank Kabel]

HZi
in Excel there's no real secure mechanismn to do this. if you want a
secure application you have to create a compiled addin (e.g. VB or C++,
etc.) No chance to achieve this in Excel/VBA (I simply would disable
macros)