you might want to create a custom module. read the docs\ https://www.odoo.com/documentation/8.0/howtos/backend.html
You can request a customization from an odoo expert or try your own.
The rough idea is like this
create a python file
from odoo import models, fields
class NewModel(models.Model):
_inherit = 'res.partner'
fdurcc = fields.Char(string="FDURCC")
And create the xml file
<?xml version="1.0" encoding="utf-8" ?>
<odoo>
<data>
<record id="res_partner_fdurcc" model="ir.ui.view">
<field name="name">fdurcc</field>
<field name="model">res.partner</field>
<field name="inherit_id" ref="base.view_partner_form"/>
<field name="arch" type="xml">
<xpath expr="//field[@name='category_id']" position="after">
<field name='fdurcc' />
</field>
</record>
</data>
</odoo>
build your module and install it. There you go....