Track a form field specific value for stats

Hi, I’ve installed piwik to use it with our ERP oracle JD Edward’s.
This ERP URL is published over citrix so user visits are recording only with citrix IP.
I’d like to track in the content the real user name logged in the ERP, for that in the main screen of the ERP I have a “user name” field.

The HTML code is that :

Do you know how to proceed and to replace visitor counters by that?

Also, which is good, I have the title of the visited pages, i’d like to hav also a supplemnatl info to make stats : each page represent a dedicated form of our ERP:

For example piwik track this :

Accès aux numéros de référence

In my HTML code I have that :

I’de like to track the P01012_W01012B_ZJDE0001 value but only a part of it : P01012 and ZJDE0001 (which represent program name and version name of the program.

I’d really appreciate if you find how.


User ID:

My question about this :
setCustomVariable(index, name, value, scope = "page"winking smiley
Can we put a result of a variable in the value parameter?
Like this?
var APPJDE=document.getElementById("formOID"winking smiley;
_paq.push([“setCustomVariable”, 2, “NOMAPP”, APPJDE.innertHTML, “page”]);