The documentation for pattern matching for Google Sheets has not been helpful. I\'ve been reading and searching for a while now and can\'t find this particular issue. Maybe I\'m
As you identified and Wiktor mentioned COUNTIF only supports wildcards.
COUNTIF
There are many ways to do what you want though, to name but 2
=ArrayFormula(SUM(--REGEXMATCH(E9:E13, "50-03[123][012]*"))) =COUNTA(FILTER(E9:E13, REGEXMATCH(E9:E13, "50-03[123][012]*")))