Custom XML response via the SOAP web service of SQL Anywhere 12?

[jan24]

I have a table
"xtable"(
  x-id int not null default autoincrement primary key,
  x-type char(16) not null,
  x-data xml
  )
where "x-type" {'x-type-1', 'x-type_2', ...} defines type of xml data and structure of "x-data" depends on "x_type"- Each "x-type" in <dose_rows> consists of diferent "x-data" structure.

I need a response from SOAP web service for example:
<SOAP-ENV:Body>
  <dose>
    <dose-header>
      <dose-id>1</dose-id>
      <dose-time>2014-05-19 14:50:01.243</dose-time>
    </dose-header>
    <dose-rows>
      <x-type-1><code>my-code</code><name>abc</name><active>0</active></x-type-1>
      <x-type-2><id>14</id><code>abc</code><catalogue>xxx</catalogue>...</x-type-2>
      <x-type-2><id>24</id><code>abxx</code><catalogue>ttt</catalogue>...</x-type-2>
      ...
    </dose-rows>
  </dose>
</SOAP-ENV:Body>

How can I achieve this custom response via the SOAP web service of SQL Anywhere 12?

Thanks
Jan