This is done through file preparation. The file is converted to RTF and the code is protected, so that CAT will recognize that it should not be translated. But how do you prepare files? This is where PrepTags comes in. (Click here to buy Preptags)
Download & install PrepTags
Preptags uses .NET Framework 3.5. This is a free download from Microsoft. If it is not already installed on your computer, please download it and install it on your computer before installing Preptags.
Once the .NET Framework 3.5 is installed, you can simply double click on Preptags.exe and follow the usual install instructions.
Here are a few videos to demonstrate the use of PrepTags.