Adding standard subject line and current date to outlook template

Question

I've been trying to add the "Automatically generated Date/Time in subject line" tool as well as a template subject line to my emails in outlook and have had no luck.

Here's an example of how I'd like the subject line to come out:

Expense Reports - 3/28/2023

The "Expense Reports - " portion of the subject line is easy enough. Even enabling a developer tool to automatically populate the date into the subject line is simple. Doing the two together, however, is my issue.

I've tried creating a .ost file, publishing forms with the formula in the subject line. All come up bust.

Any help would be greatly appreciated.

Bonus points if you can accomplish that and still allow for the two email addresses I recurringly send this email to.