finally i found a solution.
1. i created the directories
2. i put Skype.exe into .\SkypePortable\App\Skype
3. i packed my user-files previously created from another skype portable to a sfx-file (using winrar) with the following commands
(supposing the user-files are located in directory "User" you do not have to compress the whole directory but just the files located inside .\User)
4. i put the sfx-file in .\SkypePortable\Data\settings
5. i created SkypePortable.bat with following commands and put it into .\SkypePortable
start Data\settings\*.exe && start App\Skype\Skype.exe /datapath:"%temp%" /removable
6. start skype from cd by double-clicking SkypePortable.bat
you have to excange *.exe with the name of your sfx-file. after having skype closed you may use ccleaner portable to clean the %temp%-folder.