Normally, when you apply for a financial order, you have to file a second notice of acting which uses the divorce case number.
You cannot file a notice in financial proceedings as there is no application before the court. It would be like a stranger stopping you in the street to give you their new address - you would say "why do I need this, I don;t know who you are?".
In your case, whilst your solicitor may be acting for you in divorce proceedings, when/if you issue your financial application, you will include your own name and address and those are the details that the court will enter on court file.
It may be worthwhile stating in the covering letter sending the application that you are dealing with the finances yourself in case a helpful court clerk sees that there is a solicitor acting in divorce and duplicates the details.