Thanks to Hourences i can sort of solve the question.
1st: It sort of works by just adding the ProjectName right after the editor.exe unfortunately it looks for the .uproject file inside the “EngineInstallLocation/4.0/ProjectName” folder. But as he pointed out, i could simple use the Load most recent Project function located inside the editors preferences under “Loading & Saving”.
Anyway if someone knows the right way to make the editor load a specific project feel free to answer!