I Haz A Question

[badly_knitted]

Does anyone happen to know if it's mentioned anywhere in Torchwood or Doctor Who exactly when and/or how Jack came into possession of the Doctor's severed hand?

I've been asked for a drabble on the subject but I don't have time to watch all of Torchwood and the relevant Doctor Who episodes in the hopes of possibly finding something about it.

Help, please? *begs prettily*