I have been able to use the following to check for multiple items:

for my $t0_ (keys %RAD_REQUEST_PROXY_REPLY) {
   if(UNIVERSAL::isa( $RAD_REQUEST_PROXY_REPLY{$t0_} , "ARRAY" )) { }
   else {}
}

and I have been successful in editing the values and sending them to my NAS with:
$RAD_REQUEST_PROXY_REPLY{$t0_}[0]="newValue";

but I cannot for the life of me traverse the array in the hash.
I've tried all kinds of methods with foreach and for loops, but I cannot get the lenght/size of the array.
When I know i've got 3 attributes of a specific kind I can do:
   $RAD_REQUEST_PROXY_REPLY{$t0_}[0]="newValue1";
   $RAD_REQUEST_PROXY_REPLY{$t0_}[1]="newValue2";
   $RAD_REQUEST_PROXY_REPLY{$t0_}[2]="newValue3";
but I cannot find the size of $RAD_REQUEST_PROXY_REPLY{$t0_}.

Any help in the right direction would be greatly appreciated.

Tim. W