If your archive is an LTAR one, then this is the part of the script you have to consider:
get VER long
get NAMES_SIZE long
get MAIN_FLAGS long
get FILES long
getdstring DUMMY 0x1c
log MEMORY_FILE OFFSET NAMES_SIZE
math OFFSET + NAMES_SIZE
for i = 0 < FILES
get NAME_OFF long
get OFFSET longlong
get ZSIZE longlong
get SIZE longlong
if VER >= 4
get DUMMY byte # 1
get FLAGS byte # usually 9 for compressed chunks
get FLAGS long # usually 9 for compressed chunks
goto NAME_OFF MEMORY_FILE
get NAME string MEMORY_FILE
string NAME R= "_" "/"
if ZSIZE > 0
if SIZE != ZSIZE # or FLAGS & 1 (FLAGS is usually 9)
log NAME OFFSET SIZE
I don't remember if folder are archived anyway, maybe with ZSIZE zero, or not.
The script says that the path delimiter is the underscore and not the slash/backslash, so if you have a file with full name FOLDER1\FOLDER2\FILE.TXT you have to set it as FOLDER1_FOLDER2_FILE.TXT
Remember to set FLAGS to zero or 8 (you must try both) just in case the game enables compression when it's set otherwise.
The best suggestion I can give you is to make tons of tests with different settings.
The archive is probably not very complex and, apparently, there is only one field which is not parsed (DUMMY 0x1c) so you may opt for recreating it from scratch instead of editing existing ones.