DS ROMs can vary dramatically in their approach to pointers -- most older systems were either where it was in the memory or where it is was in relation to the start of the ROM or some other fixed location.
DS however has and makes extensive use of a filesystem, devs however could and did define their own systems all the time. Beyond that if the text was located in the binary (usually a file called arm9.bin when it was pulled apart, or one of the overlay files) then it will probably be pointed such that its location in memory is used instead (the arm9.bin and overlays are loaded into fixed locations in memory for that given game and they are easily found with something like ndsts or crystaltile2 so there is that).
Oh and compression can also make things fun but for the most part you point the uncompressed file and recompress it before inserting it back into the game.
Without knowing what game it is I can not do much. I have not read many pokemon tutorials of late but if memory serves then it did showcase most of the obvious/common approaches so they should get you started, however having previously read some tutorials they they do seem overly specific at times so maybe not.
I cover a few of the more common approaches in http://www.romhacking.net/forum/index.php?topic=14708
if you wanted.
More generally pointers... they point at where things are. It makes little sense to obfuscate them so the relations between their contents and the destination the game reads is usually a very simple mathematical one.