Manage hard-phone speed dials through app

I have a VVX 450 phone with VVX EM 50, which allows me to have an additional 90 speed dials.

I have been told the only way to enter those 90+ speed dials is through the VVX 450 hard-phone interface. Creating each contact on the hard phone using the T9 - "First Name", "Last Name", "Contact", and "Label" (not to mention all of the other fields) is LABORIOUS. I have even tried plugging a USB keyboard into the phone, but it doesn't work to input info into the "Add Contact" fields.

I can create favorites in the app, but they do not show up as "favorites" on the hard phone. The hard phone Contact Directory is different than the app Contacts.

Please create a way to manage "Speed dials"/"Favorites" on the hard phone from a computer interface.