Create a new PDP Page with the Custom fields and need to validate the customfield using the Published and repoting DB

Hi,

Create a new PDP Page with the Custom fields  and need to validate the customfield using the Published and reporting DB.

Process:

PMO creates new Project

Enters Name and customfield

Clicks Save button

The code then checks two things: 1) Does the entered customfield exist in the list of Projects in Reporing DB,  2) Has this customfield already been used in Project Server.

If either of the two checks above fail - the user will get an error message saying that the customfield is Invalid and project cannot be saved.

Please provide a best possible approach to do this.

Thanks in advance.