Thank you!
One more question:
I booked this flight through CM. I have 4 flight segments 2 CO Metal and 2 CM Metal - ALL are booked on CM flight numbers.

When I checked the reservation on CO.com, I saw that my PTY - IAH flight is on a CO M class. As a plat, I called the Elite line and asked for the M fare upgrade.

I'm holding now over an hour with no definite answer.
Am I entiteled for a EUA on this fare at the time of booking although it has a CM flight number? If not, will I be placed on the list for EUA begining 72 hours?

Booking code has no bearing on CO upgrades. If it is CO M then platinum elites get the insta-upgrade, assuming the ZE inventory exists. This applies even if it is booked under another carrier's code. Ditto for EUAs, where CO only cares about how it is mapped on the CO systems.

Thanks Seth but I called in twice and twice they told me that since the CO flights are numbered as a CM flight, and although it shows on my reservation as M class, they cannot do the instant upgrade.
I called COPA, they said they can't control CO upgrades...

On the COPA resewrvation it's H class....

Flight Details
Sun., Jan. 9, 2011 | Houston, TX (IAH - Intercontinental) to Santiago, Chile (SCL)
Depart:
2:17 p.m.
Sun., Jan. 9, 2011
Houston, TX (IAH - Intercontinental) Arrive:
7:28 p.m.
Sun., Jan. 9, 2011
Panama City, Panama (PTY) Flight Time:
4 hr 11 mn OnePass Miles/
Elite Qualification*:
1,770 /100% Flight: CO888
Aircraft: Boeing 757-300
Fare Class: Economy (K)
Meal: Snack
No Special Meal Offered.
Change Planes. Connect time in Panama City, Panama (PTY) is 1 hr 26 mn.
Depart:
8:54 p.m.
Sun., Jan. 9, 2011
Panama City, Panama (PTY) Arrive:
5:19 a.m. +1 Day
Mon., Jan. 10, 2011
Santiago, Chile (SCL) Flight Time:
9 hr 25 mn

Travel Time:
15 hr 2 mn OnePass Miles/
Elite Qualification*:

Total Miles:
1,770 Flight: CM437
Fare Class: Economy (K)
Flight CM 437 is operated by Copa Airlines.

Thu., Jan. 13, 2011 | Panama City, Panama (PTY) to Houston, TX (IAH - Intercontinental)
Depart:
9:55 a.m.
Thu., Jan. 13, 2011
Panama City, Panama (PTY) Arrive:
1:16 p.m.
Thu., Jan. 13, 2011
Houston, TX (IAH - Intercontinental) Travel Time:
4 hr 21 mn OnePass Miles/
Elite Qualification*:
1,770 /100% Flight: CO873
Aircraft: Boeing 757-300
Fare Class: Economy (M)Meal: Snack
No Special Meal Offered.

Platinum Elite Upgrade Fare

Does the M fare on that page not have the little yellow U icon next to it?

The flight has plenty of Z inventory which means that ZE is likely open, too. I'd give the call center a couple days to cool off (perhaps a bad pun, sorry) from the snowpocalypse and call in mid-week and explain that you would likel to upgrade your M fare. Don't mention codeshare or anything else and simply ask if the inventory is there.

Unless they've changed the rules in the past couple weeks and not announced to to anyone you should be able to upgrade that into ZE no problem.

I will say that it is a bit strange that a CM N fare maps to CO M but given the fact that they earn 150% EQMs maybe not that crazy.

Thank you!
Got the upgrade (M up to Z) after endless calls.
It wasn't easy and I had to talk to 3 agent and one supervisor but I got one of the four now nailed down.
On my PTY - SCL segment COPA C is full so I believe I will be the first CO Platinum sitting in coach with no upgrade available. I know. it can change.

Thanks again.