Custom character restriction

Hi all,

I am trying to configure the login field in the profile editor and I need the values to comply with the RUN format of chile 1234567-8, in the documentation it only shows expressions like a-z1234234, they could help me in how to validate the 12345678-9 format or what are the supported expressions since these are not explicit in the documentation.

also, I cannot control the length of the expression so that they do not enter more than the numbers allowed in the expression.

regards!