How to edit my regular expression to retrieve the first 7-8 characters of variable length strings that end with abcd.com?

I am trying to extract router names from syslog messages. Need the regular expression to get the first 7 or 8 characters of variable length strings that end with abcd.com. Example below: tpbjm01-re0.abcd.com xtsdjm01-re0.abcd.com lnd2j902-re1.abcd.com pqrjm02-re1.abcd.com py3jm01-re1.uk.abcd.com brhmjm02-re1.emea.abcd.com rcnj902.abcd.com cpzyjm01.abcd.com So result should be: tpbjm01 xtsdjm01 lnd2j902 pqrjm02 py3jm01 brhmjm02 rcnj902 cpzyjm01 This is supposed to be the correct regex but it is not pulling anything: ^(?\w{7,8})(?=.*abcd.com)