adding existing calls of docbook to new elements

[KemperR]

Dear Experts,

I'm new to docbook and have sucessfully started to get into
customisation layers. Therefore I changed the dtd as recomended.
But I got stuck at the simple point when I want to add existing classes
to my new elements.
E.g I would like to see every thing of the para.class to my new element
eeabastract. Please find my DTD below:
My problem is that I can only refer to an existing class after
%DocBookDTD is called. But than I ca not longer add things to it.

How to make this right ???

Thanks a lot for your help
Rolf

<?xml version="1.0" encoding="UTF-8"?>
<!-- eefrontpage -->
<!ENTITY % eefrontpage.module "INCLUDE">
<![%eefrontpage.module;[
<!ENTITY % eefrontpage.element "INCLUDE">
<![%eefrontpage.element;[

<!ELEMENT eefrontpage
(docnumber+,doctitle,docsubtitle,department,effectivedate,approvedby,checkedby,issuedby,distribution)>
<!ELEMENT docnumber (#PCDATA) >
<!ATTLIST docnumber type (EE|IDS) #REQUIRED>
<!ELEMENT doctitle (#PCDATA) >
<!ELEMENT docsubtitle (#PCDATA) >
<!ELEMENT department (#PCDATA)>
<!ELEMENT effectivedate (#PCDATA)>
<!ELEMENT approvedby (#PCDATA)>
<!ELEMENT checkedby (#PCDATA)>
<!ELEMENT issuedby (#PCDATA)>
<!ELEMENT distribution (addressee+)>
<!ELEMENT addressee (#PCDATA)>
<!ATTLIST addressee type (TO|CC) #REQUIRED >
<!ELEMENT eeabstract (#PCDATA)> <!-- how to add existing docbook
classes here e.g (para.class) here ????? -->
]]>
]]>
<!-- eedocstate -->
<!ENTITY % eedocstate.module "INCLUDE">
<![%eedocstate.module;[
<!ENTITY % eedocstate.element "INCLUDE">
<![%eedocstate.element;[
<!ELEMENT eedocstate (#PCDATA)> <!-- how to add existing docbook
classes here e.g (para.class) here ?????-->
]]>
]]>

<!ENTITY % local.info.class "|eefrontpage|eedocstate">
<!ENTITY % DocBookDTD PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
"J:\etccom\_work_rolfk\_cdGeneral\_xml\_docbook\DTD4.4\docbookx.dtd">
%DocBookDTD;