Please help me translate content of a certificat in Latin

The European Academy
of Scientific Methods and Scholarships

Bears witness

<name of guy>

For the most distinguished reasons (or merits)
is appointed to be

Associated Member

First Chief Secretary
we bestowed [in] Paris
2004

- - -
Two things I have difficulty with and you may need clarification on:

Participem Associatum - i use
as-sŏcĭo, āvi, ātum = to join to or unite with a person
partĭceps, cipis = a sharer, partaker, partner

Scriptor Principalis Praeses - i use
scriptor, ōris = a writer, scribe, secretary
princĭpālis, e = first in rank, station, or esteem
praeses, sidis = a chief, ruler, president

Clarification
Dear Africanus,
Thank you very much for your help.
The text I posted is found to be correct except that Scriptor Principalis Paraeses should be read as two separate titles, that is Scriptor Principalis (under this is the signiture of one person/first secretary?) and Praeses (the signature of another person/President?).

Thanks again