Theoretically possible, yes.
A good idea? No.
At a high level, your web interface would have to generate dbedit commands.
In terms of modifying an existing rules or creating/modifying objects, that can be done.
Adding/deleting rules can also be done, but it's far from simple as there is no such operation as "insert."
Not to mention that you'll have to have logic to deal with the fact that, when the dbedit commands are run, an admin might also be connected in read/write mode, causing those commands to not work.
As well as deal with a few other possible concurrency issues that might come up.
Also keep in mind that we have limited documentation available for dbedit.
And, given that R77.x is End of Support, you're basically on your own if you run into any issues.
You're really better off upgrading to R80.x.
If you absolutely must still run gateways on R77.30, at least upgrade the management to R80.x, which will allow you to use the management APIs.
The Management APIs are far simpler and better documented than dbedit ever was.