Magix added a new command into Movie Edit Pro in May of 2018 to move the contents within a trimmed clip to select a new starting position, without having to re-trim the clip. This tutorial shows where the feature is, how to use it on a trimmed clip, and also shows that you can use the Object Trimmer to do the same thing but with more accuracy. This feature is in Movie Edit Pro Plus/Premium and Video Pro X (not sure about the basic program).