Yes, but with extreme difficulty. If you have an original 2007 Retail Code, here is the only way to use it without buying a new product key:
Some cheap "NEW Retail Codes" are region-locked to Russia, Brazil, or Asia. If you live in the US or EU, a RU/CIS key will require a VPN to activate on Steam – which violates Steam’s terms of service. Always look for "Global" or "Region Free." Yes, but with extreme difficulty
Between 2010 and 2013, Relic Entertainment and THQ ran a program called the "Company of Heroes New Steam Version" migration. During this period, you could enter your old CD Product Key into a specific website, and it would grant you a free Steam key for all three games (CoH, Opposing Fronts, Tales of Valor). Always look for "Global" or "Region Free
That program is now closed.
Company of Heroes: Opposing Fronts is not available on GOG (DRM-free store) as of 2025 due to middleware licensing. Do not try to redeem any key on GOG – it will not work. The only modern platforms are Steam and the defunct Relic Online. Company of Heroes: Opposing Fronts is not available