$re = '/^(?<nname>[^,]+),(?<Id>[^,]+),(?<app>[^,]+),(?<Time>.*)/m';
$str = 'CSV Content:nname,Id,app,Time
mule_330299_prod_App01_Clt1,91826354-d521-4a01-999f-35953d99b829,870a76ea-8033-443c-a312-834363u3d,2023-12-23T14:22:43.025Z
mule_29999_dev_WebApp01_clt1,152g382226vi-44e6-9721-aa7c1ea1ec1b,26228e-28sgsbx-943b-58b20a5c74c6,2024-01-06T13:29:15.762867Z ';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php