Longer Extended description field for Amazon?

We don’t use the RMS extended description field because on our Nitrosell site we incorporate lots of links and html which are prohibited by Amazon. We have set up another field in PAM to use as an extended description for Amazon but it’s very character limited causing us to have to leave out lots of information on many of our products. Is there any way to create a field without PAMs character limit? We really don’t want to have to strip out our own website to accommodate Amazon.