How to call / push an elem to a hash of array ?

[LI NGOK LAM]

my (%LIST, @other_list);

@other_list = ( Unknown Length Data Elems );

foreach my $col (@lists)
{
    for (@other_list)
    {  
        if ( exist $LIST{$col}[0] ) { Do_smth_2 }  # But ERROR either
        
        What should I write here ? So can push vars to $LIST{$col}
    }
}


Thanks in advise