Could this be a quoting problem? What OS?, etc, as above

You need to provide better specs on your problem or you'll be fortunate to get anything more helpful than wild guesses ( except, of course, advice to be more specific :-) )...
like this:

C:\>perl -E "my $foo = 'v=8'; say $foo;"
v=8
[download]

So, drink your veggies and be concisely comprehensive: that is, provide code and warning or error messages, if any, and explain what you're trying to do.