On Thu, 28 May 2009 05:31:01 -0700, FARAZ QURESHI
wrote:

How can I have a UDF, which is saved in an addin installed, be applied in the
conditional formatting? Because upon applying a conditional formatting like
=NOT(ISFORMULA(A1))
so as to highlight the cell(s) without a formula results into a popup of:

You cannot use reference to other worksheets or workbooks for Conditional
Formatting criteria.

Put the UDF in some "other" cell. Then execute your Conditional Formatting
based on the contents of that "other" cell.
--ron