Time to command - latest seniority list (about 6 months old) shows 1300 pilots, of which 450 are Captains (figures rounded off to help the math). That leaves 850 pilots ahead of you, each and every one of which will be offered command (on any type, freighter or pax, as chances permit) before you.
CX's last three years has seen 20 upgrades per year. A long term average is 40. The maximum ever is 60-ish (we don't have the training resources to do anywhere near this many today). Maybe if we expand enormously we could have a future average of 80, if you are optimistic.
Using 20-40-60-80 as estimates of future command upgrades, time to command will be 42, 21, 14, 11 years respectively.
Another method - Today's new captains joined ahead of S/Os (who spend 2-3 years before becoming F/Os), and they took 10-11 years, having joined in '89-'90. Total time, 12-14 years. Two different ballpark methods give approximately the same ballpark answer.
Mis-information - current freighter pilots joined out of seniority, in a management attempt to split the pilots and drive down salaries. They have the protection of 3:1 (or is it 4:1?) offer of commands, ie 3 freighter pilots will be offerred command on the freighter for every 1 CX pilot. This is NO LONGER open to those who join after 1 Jan 2000 - you will be on the seniority list like everybody else.
Bottom line, 11-14 years to command. That assumes that the current contractual seniority list holds. CX management love to fiddle contracts, but if you read the other threads I'm sure you know all about that.