California department of real estate will license a validly established California corp ( C or S) requiring a licensed real estate broker to be identified as the broker on charge and DRE requires a physical office address but you could use a box address as a mailing address if you chose to have it separate.
The "s" election for a corporation is a federal taxation category which amongst other benefits allows for "pass through" taxation to the individual (s) tax payer/shareholder of S corp.
You could employ the services of a business attorney to properly structure and form your intended venture and take care of your DRE filing requirements as well as the Secretary of State and ca department of corporation.
Beat of luck.
The virtual office can be used as the registered agent address; however, make sure that the instructions that you leave with Regus are explicit. If they accept mail as your registered agent, then your time period for responding to any complaints received by them will begin on the date of their service. Thus, you must make sure that you receive any documents that they are served on the same day as their receipt.
You should be able to use a virtual offices address as the address of your Real Estate Corporation. Many companies do this as they transact business in these virtual offices, and a common receptionist representing your company etc.