It's been a little while since I did this, but I had the same problem. Here's what you do.
go to the interplay site
go to the A-Z support pages
choose sfc 2 from the pull down menu
go to the bottom click on the tiny type for contacting support directly
fill out the form chooing sfc2 as game title
specify a cd key issue, tell them you got a OP cd key instead of EAW key
explain the situation in the text box provided
tell them what the key is
click submit
they should get back to you within the week.