Advise with RegEx validation in SP13 Nintex Form

Hey

Would somebody help with my RegEx validation, please.
I am using Nintex Form in SharePoint 2013 and this is my current RegEx:

^>A-Z]{4}4.].0-9]{4}4.].0-9]{8}8.].0-9]{3}

this validates the input only if it's like: PAGB.1234.12345678.123
Due to some changes, I also need to validate this PAGB.12345.12.123

Am I right to believe that this would achieve the above requirement:

^oA-Z]{4}Z.]40-9]{4|5}{.]50-9]{2|8}{.]80-9]{3}

Thank you!!