Large Numbers of Compartments

Hello, I have a model where I will likely need between 130 and 150 compartments (it's a rich data set and many transit compartments, so it is probably estimable). When I was looking in SIZES, it indicated that the maximum number of compartments is 99; I was wondering if there is a way around this limitation? Alternatively, is there another tool that people would suggest that can handle mixed effects with a large number of diff eqs and dosing? Thanks, Bill Notice: This e-mail message, together with any attachments, contains information of Merck & Co., Inc. (One Merck Drive, Whitehouse Station, New Jersey, USA 08889), and/or its affiliates Direct contact information for affiliates is available at http://www.merck.com/contact/contacts.html) that may be confidential, proprietary copyrighted and/or legally privileged. It is intended solely for the use of the individual or entity named on this message. If you are not the intended recipient, and have received this message in error, please notify us immediately by reply e-mail and then delete it from your system.