use warnings;
use strict;

while (<DATA>) {
    chomp;
    
    if (! m{
            /(\d+)                  # Get first bunch of digits following a /
            .*? Date\sTime\s        # match date time string
            ( (?: (?! \s\d+/). )+ ) # Everything up to the space before \d+/
            [^/]+ /                 # Throw away the unwanted digits preceeding /
            (\d+)                   # Grab last number
            (.*)                    # Grab tail for subsequent checking
            }x                      # allow most white space and comments
       ) {
        print "No match: $_\n";
        next;
    }
    
    my ($first, $datetime, $last, $tail) = ($1, $2, $3, $4);
    if ($tail =~ /(\) | \.sta \)?) $/x) {
        print "Skipping $_\n";
        next;
    }
    
    print "Extracted $first, $datetime, $last\n";
}

__DATA__
12345645/883700892.log Date Time 4 kkdjkdkd 889298383/883729083.dat
12345645/883700892.log Date Time 4 kkdjkdkd 889298383/883729083.sta
(12345645/883700892.log Date Time 4 kkdjkdkd 889298383/883729083.dat)
(12345645/883700892.log Date Time 4 kkdjkdkd 889298383/883729083.sta)
Completely badly formed

##</code><code>##

Extracted 883700892, 4 kkdjkdkd, 883729083
Skipping 12345645/883700892.log Date Time 4 kkdjkdkd 889298383/883729083.sta
Skipping (12345645/883700892.log Date Time 4 kkdjkdkd 889298383/883729083.dat)
Skipping (12345645/883700892.log Date Time 4 kkdjkdkd 889298383/883729083.sta)
No match: Completely badly formed