Email sales order confirmation from ISA CRM 4.0

Hi,

I'm currently working on an implementation of SAP CRM 4.0 Internet Sales.

I have a requirement to change how the sales order confirmation is emailed out... We want to allow some custiomers to specify a different email address for their confirmations to be sent to - so instead of the system taking the standard address from the user master it will take it from a custom (or alternative standard) email field.

Has anyone done anything similar and suggest possible solutions to this?

Thanks in advance.