Regular Expression for Custom Fields ( SSH Port )

[Tamer Fahmy]

Hello,

I'm looking for Regular Expression Validation String for a custom field used as SSH Port
for example i need the user to select a number between ( 2000 and 9999 ) or default port 22 

How to validate this with the Regular Expression Validation String
I tried to use

\d*^[2-9]\d{3}|22

but it is not working
Any advise

Regards