XML entity with parameters?

I want to achieve a resulting XML below, but with modular XML parts

<createTable schemaName="mySchema" tableName="myTable">
     <column name="Id" type="int" />
</createTable>

I have externalized the xml into DTD Entities

myDTD file:

<!ENTITY createDefaultTable "
   <createTable schemaName="${schema}" tableName="${table}">
     <column name="Id" type="int" />
   </createTable>
   ">

myXML file:

 <!DOCTYPE defaults SYSTEM "myDTD">
 &createDefaultTable;

But my missing link is, how can I pass parameters ${schema} and ${table} to be added into my entity from "myXML" file?