Hello Rajko and welcome !
The issue is related to the command line parameters. I know it is a bit tricky, sorry.
The best way to see what Siren does is to do it by step, not using "/R" and "/Q" at first.
If you just start your command line without them:
Z:\Siren\Siren.exe /D "X:\bilderarchiv\2008-07-19" /F "crw*.crw" /S "*" /A 10D /P
You'll see that no files have been selected for the rename operation.
The "/F" switch applies a filter to the file list but doesn't select them. In fact it "fills" the filter combo edit box as you would manually do.
You've got to use the "/S" option in place or in conjunction of "/F" depending on your directory content.
Z:\Siren\Siren.exe /D "X:\bilderarchiv\2008-07-19" /F "crw*.crw" /S "*" /A 10D /P /R /Q
Z:\Siren\Siren.exe /D "X:\bilderarchiv\2008-07-19" /S "crw*.crw" /A 10D /P /R /Q
Using "/F" should reduce a bit the directory time loading by avoiding the meta data extraction of files you don't care of.
Siren command line features is not limited to batch renaming but to Siren GUI initialization too.
Hope this will help.