File number in renaming

[digikam at 911networks.com]

DK 5.7.0 on archlinux.

Is there a "file number" function in the renaming?

DSCF1234.RAF.

I want the 1234 that I want to keep. Right now I'm doing
[file]{range:4,8}. This works if all the files are named aaaa9999 but
sometimes they are named: what-ever-name-20171105-1234.xxx

I want to keep the 1234, I don't want to start a new counter. An
right now I have to do this manually, instead of a batch or a whole
album...

-- 
sknahT

vyS