Auto Increased Opportunity number

Dear all,

We are trying to create auto numbering for the opportunity in 7.10.

So far this is what we did.

1. Create system settings for OpportunityCodeMask, OpportunityLastNumber

2. Create a replace module of "Opportunity" and add a new field UsrCode

3. Create an object process contains the following task:

       1) message start with message: OpportunityInserting

        2)ScriptTask "SetNumberGenerationParameter" with code:

        3) a user task "GenerateNumberUserTask", task type "Generate ordinal number ( Base )"

        4) as Script task "SetGeneratedNumber" with code 

3. Save and publish this process.

However after I create an opportunity, the code is not filled in the newly created opportunity.

I got this from the following URL:
https://academy.bpmonline.com/documents/technic-sdk/7-10/how-add-auto-nu...

But I did not implement the onEntityInitialized method in the OpportunityPageV2 because I would like to have this number whenever an opportunity is created (copied or created manually, maybe via web services later on).

Is there anyone who had the same situation before?

Some help will be appreciated.