Please add [#licenseno#] email template variable

Our customers are finding it difficult to find their license key for digital purchases.
We keep having to explain to them to go to their order and click on the green license key icon.
It would be much better if we could add their license key to the conformation email they receive.
There is already a [#orderid#] and [#items#] so why not add a [#licenseno#] variable?

Thanks.
Simon.