Actually, I didn't need /interactive.

>type c:\script.pl
open(my $fh, '>>', 'c:\\script.out') or die;
print $fh (scalar(localtime()), "\n");

>at 1:59 perl c:\script.pl
Added a new job with job ID = 1

>at
Status ID   Day                     Time          Command Line
----------------------------------------------------------------------
+---------
        1   Today                   1:59 AM       perl c:\script.pl

>time
The current time is:  1:59:36.77
Enter the new time:

>at
There are no entries in the list.

>type c:\script.out
Sun Apr 13 01:59:00 2008
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