So, you unpack mpq archives and have many text and dialog files (located in rez mainly).
You want to edit that file for some reason, how to do that?
Here are these 2 utils: binedit and tblpad.
I just tried and they works for me.
Also note that these extensions doesn't guarantee compatible file format (for example ai.bin is not the file to open with binedit). Also some files with improper extensions could be opened by these utilities. Appreciate if you post some additional details about how to open other files.