[QuantlibXL] how to make exported functions non-volatile

[radupaul]

Hi:

How can I ensure that the functions exported by QuantlibXL are registered with Excel as non-volatile? I understand that somehow I should pass a parameter to the xlfRegister function ?

I am optimizing a big spreadsheet and a large chunk of time is used by re-calculation of volatile functions (without any of the arguments changed).

I appreciate the help (with some details, where should I look, in the QuantlibXLStatic  register folder, etc ...?)
Thank you,
Radu