That will work, but not under strict 'refs'. Symbolic references are considered bad practice (but you can't always avoid them).

$testing = "Hello, World!\n";
$var = "testing";
$data = $$var;
print $data; # prints Hello, World!
[download]

$hash{"testing"} = "Hello, World!\n";
$var = "testing";
$data = $hash{$var};
print $data;
[download]

Apparently this FAQ is not easy to find, since the question gets asked regularly.

Re: Create an array reference from a string offers helpful input from Corion and dragonchild.

So you've done something like this?

$var="\$somevariable";
[download]

$data=$var
[download]

$data="$somevariable"
[download]

$data=$somevariable;
[download]

See Re: variable with $$.