Please Help Creating Custom Token!!

Hi people! first of all thanks for you time!

I'm setting up a drupal action which will help me to fill up an email with the contents of an users post.
The site is a simple advertising community site where users can sell or exchange objects. They post an ad using a created content type page for publishing a selling post, or using an exchange type content for publishing an exchange ad.

I would like to send a copy to myself via email of the users ads (when they publish one) filling up the email using tokens. Till here no problem i print the message body of the user document/post (with token [node:body]) then the content type of the document (using token [node:content-type]) and then i need to use the token [node:field_ref_vocabulary_selling] or [node:field_ref_vocabulary_exchange] depending on the content type the user used for creating the document (selling or exchange) in order to show which field_ref_vocabulary he selected from the selection list.

[node:body] [node:content-type] then depending on this content type i will be using [node:field_term_selling] or [node:field_term_exchange]

[message body] [exchange] [books]

[message body] [selling] [bikes]

Taxonomy/vocabularies: (I created 2 vacabularies because i don't want to use one selection list where all the categories are on it since the list might grown in the future and then could be annoying for the user).

selling:
cars
bikes
computers
clothes

exchange:
books
habilities
presents
others

I'm explaning myseld so bad! SORRY!

Thanks for your help!