Storing a 'group sms message' under a specific person

Hi All,

From my HTC Desire S, using the default Message app, I have just sent a 'group' SMS to a single person. For reasons unknown, my friend has 2 phones, so occasionally I send to them both - so the group SMS sends to 'personA', 'personA', but with different mobile numbers...

What I would like to do, is save my 'group' sent message as part of the conversation with personA (where it already holds the conversation where I have only used one of the 2 numbers).

Is this possible??

Many thanks.