Texas Instruments Page/Register Convention - how to find the actual register address?
As per page 75 in the datasheet:


  In any page, register 0 is the Page Select Register. The register value selects the Register Page from 0 to 255
  for next read or write command.


So as far as I understand, the correct sequence to write register R on a page P, would be:
1) Write the number P into address 0 (using the steps you have described in the question) 
2) Write the desired value to the address R (using the steps you have described in the question) 

As for example in your question - first write 0 into address 0, then write the configuration data into address 3. 
I believe the first step can be skipped for subsequent reads/writes on the same page.