Which version of JBoss as you using?
For JBoss AS 4/5, you may look at the following article which explains how to use the "JNDI Binding Manager" :
In JBossAS7 you can bind custom objects in the JNDI tree of JBoss, However i do not think that you can define a custom URL name space for JNDI binding because JBossAS7 strictly follows EE6 specifications. EE6 defines some very standard JNDI name prefixes. However if you want to bind some custom objects in the JBossAS7 jndi tree then you can use the "object-factory" in the naming subsystem as described in the following article:
Binding & Remote Lookup of Custom Objects in JNDI tree of JBoss AS7.1.1