How to query for headers by regexp?

[Ralf Hildebrandt]

I need to find all mails with a certain numerical range in my quarantine:

X-Spam-Status: No, score=4.5 tagged_above=2 required=4.6 ...

Assume I'd be looking for 4.5-6.0; so I tried searching for

doveadm import -u restore mdbox:/home/quarantine/mdbox "" \
   mailbox INBOX header X-Spam-Status  "No, score=4.5"

doveadm import -u restore mdbox:/home/quarantine/mdbox "" \
   mailbox INBOX header X-Spam-Status  "No, score=4.6"

etc.

Which would only return 2 Mails, with score score=4.5
What am I doing wrong here? Can I search using regular expressions?

-- 
Ralf Hildebrandt
  Geschäftsbereich IT | Abteilung Netzwerk
  Charité - Universitätsmedizin Berlin
  Campus Benjamin Franklin
  Hindenburgdamm 30 | D-12203 Berlin
  Tel. +49 30 450 570 155 | Fax: +49 30 450 570 962
  ralf.hildebrandt at charite.de | https://www.charite.de