Upper and lower case strings in Varnish

[Richard Chiswell]

Hi all,

I've got a simple question which I've been puzzling on for the last 30 
minutes or so - how do you change a string in Varnish to lowercase?

Basically, all the links on our site should be lowercase, but some 
people have been randomly capitalising them when linking to them - I'd 
just like Varnish to issue a 301 redirect to the lowercased version of 
the URL: everything is in place apart from converting the string to 
lowercase.

Any advice welcome!

Thanks,
Richard