diff --git a/Assets/CodeGen/BMapBinder/ExpFctsExtractor/main.py b/Assets/CodeGen/BMapBinder/ExpFctsExtractor/main.py
index 2f02409..cba2373 100644
--- a/Assets/CodeGen/BMapBinder/ExpFctsExtractor/main.py
+++ b/Assets/CodeGen/BMapBinder/ExpFctsExtractor/main.py
@@ -1,23 +1,63 @@
-import os, re
+import os
+import re
+from pathlib import Path
+
+# region: Path Getter
+
+
+def _get_libcmo21_repo_directory() -> Path:
+    repo_root = os.environ.get("LIBCMO21_REPO_ROOT", None)
+    if repo_root is None:
+        return Path(__file__).resolve().parent.parent.parent.parent.parent
+    else:
+        return Path(repo_root).resolve()
+
+
+def get_input_file_path() -> Path:
+    return _get_libcmo21_repo_directory() / "BMap" / "BMap" / "BMExports.hpp"
+
+
+def _get_bmap_binder_directory() -> Path:
+    bmap_binder_root = os.environ.get("BMAP_BINDER_ROOT", None)
+    if bmap_binder_root is None:
+        return Path(__file__).resolve().parent.parent
+    else:
+        return Path(bmap_binder_root).resolve()
+
+
+def get_output_file_path() -> Path:
+    return _get_bmap_binder_directory() / "Extracted" / "BMExports.hpp"
+
+
+# endregion
+
+# region: Extractor
+
+# We should not only match BMAP_EXPORT,
+# because it may match the defination of BMAP_EXPORT.
+# So we add a bool at head because all BMap functions return bool.
+EXPFCTS_PATTERN: re.Pattern = re.compile(
+    "^BMAP_EXPORT[ \\t]+bool[ \\t]+[^;]+;", re.MULTILINE
+)
+
+
+def extract_expfcts(infile: Path, outfile: Path) -> None:
+    with open(infile, "r", encoding="utf-8") as fin:
+        # read full text
+        fulltext: str = fin.read()
+        # do findall and write into file
+        with open(outfile, "w", encoding="utf-8") as fout:
+            for item in EXPFCTS_PATTERN.findall(fulltext):
+                fout.write(item)
+                fout.write("\n")
+
+
+# endregion
+
 
 def main():
-    self_path: str = os.path.dirname(__file__)
-    src_file: str = os.path.join(self_path, '../../BMap/BMExports.hpp')
-    dst_file: str = os.path.join(self_path, 'dest/BMExports.hpp')
-
-    with open(src_file, 'r', encoding='utf-8') as fsrc:
-        # read full text
-        fulltext: str = fsrc.read()
-        # do findall and write into file
-        with open(dst_file, 'w', encoding='utf-8') as fdst:
-            # We should not only match BMAP_EXPORT,
-            # because it may match the defination of BMAP_EXPORT.
-            # So we add a bool at head because all BMap functions return bool.
-            for item in re.findall('^BMAP_EXPORT[ \\t]+bool[ \\t]+[^;]+;', fulltext, re.MULTILINE):
-                fdst.write(item)
-                fdst.write('\n')
-
-    print('DONE')
+    extract_expfcts(get_input_file_path(), get_output_file_path())
+    print("Done")
 
 
 if __name__ == "__main__":