Is there a custom function that will allow me to pull Info from CRM into an Estimate

Is there a custom function that will allow me to pull Info from CRM into an Estimate

Hi All,

I am trying to work out some automation and not sure where to start,
Currently i need to Automate pulling my Deal Number from CRM and have it show inside an Estimate when i create it.
i.e. CRM.Deal_Number -> CustomField "Deal Number" 
I have not been able to find anyone who has been able to pull data from crm into books

A similar but separate issue is trying to write a custom function to Add Headers and Items to my Estimates on load.