I'll preface this reply by suggesting you might want to talk to Support to see if there is a better way for your purpose - depending on how many Licenses are involved ....
But so far as I can see the only way of discovering per machine the specific Activation Code used is to head into the Deactivation routine using the License Manager until that code is presented on screen. Then cancel the process to leave things unchanged.
The link may help. It refers to V15 but as far as I know V14 is the same. You may want to read a few of the other pages around the linked page for the full comfort factor.
I'm assuming no one has a list of which activation code was used for which machine ... ? Hence why you need one now?