Its a external solution (I want to get that data from my trailhead dev org) and it exposes empolyeers info, even its Trailhead info, its not proper, I guess. But thank you for your suggestion. Maybe there is not an apex code to display trailhead related account data, just web scrapping, etc. I want to display this data over salesforce dashboards and graphics, so SF would fit perfectly. Stil havent found any solution using SF..
In fact, theres an app in appexchange but it does not cover all the trailhead informations (like account points) and its sync is not precisely refreshed
However, your employees need to login with their trailhead accounts and link it. Hardly a 1 min process.