Link Failover and NAT problems and MANGLE problems.....

I have a couple of problems with my mikrotik and i have to deliver a solution to a Telco asap…They want me to configure a fail over for the internet for their PDSN…I have no problems with the failover config…just that on one of the routes, they want me to creat a NAT to an address not present on the physical interfaces…i dont know how to go about dis…the actual connectin interfaces have an address 10.10.x.x/30 but dey want me to do a NAT to 212.x.x.x/29…and dey claim that their equipment at d oda end would understand the packet.please help me out…also i would like an explanation for what a mangle is used for…when and how to use it…what i read was a lil confusing…yeah i know mikrotik is gud but it aint user friendly…

Pls get back to me asap…

My friend this is serious business you are dealing with. ‘Telco’ must pay you good, and you must study MikroTik manual good to do the job for them.

Please paste the configuration of the router and try to explain with even more details, what needs to be NATed to what.. ?