it would be helpful for you to tell us WHICH version/edition of ACL you are using.
Assuming your version has such a feature, there are left and right channel level controls in "Stereo FX".
You can also use a proper audio editiing software. If you don't have MAGIX Music Maker, Music Studio, or Samplitude, then I suggest the freeware Audacity.
In an audio editing software, you can control the track channel levels using the Pan control in the mixer.
Or, you can split your stereo track into separate left and right channels. Then, you will be able to control the volume levels of each channel as an individual track in the mixer..
There is no need to post your question twice in the different language forums - if you set your Search settings for the forum as shown in the image below you will see answers from the UK and US members.