Add user defined fields in the FIX dictionary - quickfix

Question

I need to add/modify fields in the FIX4.4 dictionary. I haven't found any helpful documentation or tutorials on this.
I'm guessing I have to modify the FIX44.xml file, but I'm not sure how exactly to do that.
In the <message></message> tags I don't see any attributes that define the number or the type(format) of that field. I see just the name and required attributes.
I think I found attributes I', looking for in the <fields></fields> tags.
I'm not sure if I'm looking in the right place or if I'm doing the right thing, but according to this I should modify the dictionary if it is necessary.
Please help.
A link to a tutorial for beginners that can help me would also be greatly appreciated.

Answer 1

The FIX Data Dictionary in QuickFIX contains Messages and Fields (among other things).
To add Messages you must add the message between the <messages></messages> tags like this:
<message name="CoolMessage" msgcat="app" msgtype="xCM">
<field name="Currency" required="N"/>
<field name="Text" required="N"/>
<field name="Account" required="Y"/>
</message>
And then add the new msgtype to the MsgType field in the <fields></fields> section like this:
<field number='35' name='MsgType' type='STRING'>
...
<value enum='xCM' description='COOLMESSAGE'/>
</field>
If you want to add new fields, just add them between the <fields></fields> tags like this:
<fields>
<field number="1" name="Account" type="STRING"/>
<field number="2" name="AdvId" type="STRING"/>
<field number="3" name="AdvRefID" type="STRING"/>
...
<field number="9006" name="AwesomeField" type="STRING"/>
</fields>
This and more information can be found in this tutorial.