Assuming you edited the dlg file using the dlgeditor and put the script in the Script Fire section, and placed it into the override folder. Then I think your issue is saving the script.
SetGlobalBoolean("EhWarp",TRUE); /// This is completely useless.
Booleans in kotor work on referencing the globalcat.2da file, like memory keys, they have to exist in the globalcat.2da file, else they won't have any impact.
However, I'd recommend not including this at all merely because it is completely unnecessary to warp the player from one location to another.
Unless you have a good reason to do so, then you'd want to edit the global.2da and add a line to that with your tag "EhWarp" and label it as a Boolean.
The rest of your script is correct,
void main() {
StartNewModule("tag of module goes here");
}
However, you'll need the nwsscript.nss in your override, which you can extract using the Kotor Tool in the source script section of the BIFs.
Finally, you'll want to set the script to K1 script, then compile it by selecting "compile" which will ask you to save it somewhere, save it as "whatever.nss" the .nss is very important, then it will compile as a .ncs file. You'll end up with two files, the .ncs is the compiled/working version, while the .nss is the source script.
After you've finished remember to put all the files in the necessary folders within kotor, in this case 2da files, scripts, dlg files can all go into the override.