To use this feature, you do not need to do anything apart from configuring a list of non-translatable phrases. If you move the cursor to a previously untouched segment (where no translation memory hit or manual typing was inserted), memoQ first scans the translation memories, then the term bases and the lists of non-translatable phrases.
When memoQ scans the source segment for non-translatable parts, it automatically highlights those found in the source cell, allowing you to insert the desired target version manually. Non-translatable parts are highlighted in the gray color, and they appear as a gray hit.
In a memoQ project, you can use several non-translatable lists. One of those will be the primary non-translatable list where you can add new non-translatable expressions while you are working in the translation editor.