Default Applications - Can't select Outlook 2013

Hi,
I have Office 2016 but have to use Outlook 2013 due to Exchange limitations for my corporate email account
All works well except when choosing default applications the list only has Outlook 2016
This is a problem as I want to configure the MAILTO (URL:MailTo) protocol to Outlook 2013 (the version I use)
I can't have both versions running together so how can I edit the list/select Outlook 2013 when choosing the default apps for email/MAILTO?

hi dalchina. Thanks for your reply but still no luck. :-(
Oddly the registry option nearly works in that if I edit the key value to Office15 I can then launch a blank email when I run the string via command line (CMD).
However, no luck when clicking a mailto: link in say an email. It thinks about but then nothing.

My default is Outlook 2016 so I just edited the parameters for Outlook 2013 as follows
"C:\PROGRA~1\MICROS~1\Office15\OUTLOOK.EXE" -c IPM.Note /mailto "%1"
Only Outlook 2016 appears in the lists, even after changing the registry key as above.

All I changed was Office16 to Office15 and as I said earlier if I run the parameters via CMD then a a blank email opens
Sorry to be so vague

When I upgraded to Office 2016 I realised quickly that I couldn't even open my corporate account so I did no further testing followed by uninstalling Outlook 2016 and reinstalling Outlook 2013.
Unfortunately the Send to throws a related error too (even though the key value is otherwise correct).

The popup appears to suggest that Send to was trying to use Outlook 2016 but the key value says different