[Users] Routing to NATed gateways

Hi, I'd like to use OpenSER for routing calls to NATed gateways. I also want to support the LCR feature. Unfortunately, the current LCR module doesn't support NAT. I mean that the gateway IP addresses must be defined explicitly in the "gtw" table. Now I'm looking for a way to force OpenSer to use information from the "location" table. I want to write a module that will have the similar functionality like the current LCR module has but resolving procedure will be more complicated (not based on prefix and From only). The module should build avp list where each gateway will have symbolic user name. For example, g1, g2 etc. The gateways will also be registered on the proxy with those names. Then I think it will be possible to call lookup("location") after successful call the next_gtw() from the script. Is it feasible? Is there another way to solve my problem? Thank you in advance, Leonid Fainshtein