diff --git a/tren.py b/tren.py
index 0c889b2..cfa2d5c 100755
--- a/tren.py
+++ b/tren.py
@@ -8,7 +8,8 @@
 PROGNAME = "tren.py"
 BASENAME = PROGNAME.split(".py")[0]
 PROGENV  = BASENAME.upper()
-RCSID = "$Id: tren.py,v 1.217 2010/04/07 18:36:55 tundra Exp $"
+INCLENV  = PROGENV + "INCL"
+RCSID = "$Id: tren.py,v 1.218 2010/06/25 22:39:46 tundra Exp $"
 VERSION = RCSID.split()[2]
 
 # Copyright Information
@@ -64,9 +65,12 @@
 elif OSNAME == 'posix':
     POSIX = True
 
-# If we're on Win32, try to load win32all stuff if it's available
-
+# Set up Windows-specific stuff
+    
 if WINDOWS:
+
+    # Try to load win32all stuff if it's available
+
     try:
         from win32api import GetFileAttributes, GetComputerName
         import win32con
@@ -79,13 +83,18 @@
     except:
         WIN32ALL = False
 
-
-# Get Unix password and group features
+# Set up Unix-specific stuff
 
 elif POSIX:
+
+    # Get Unix password and group features
+
     import grp
     import pwd
 
+
+# Uh oh, this is not an OS we know about
+
 else:
     sys.stderr.write("Unsupported Operating System!  Aborting ...\n")
     sys.exit(1)
@@ -102,7 +111,6 @@
 #----------------------------------------------------------#
 
 
-
 #####
 # General Program Constants
 #####
@@ -156,6 +164,9 @@
 NULLRENSEP   =  "Old/New separator string"        # Cannot be null
 NULLSUFFIX   =  "Forced renaming suffix string"   # Cannot be null
 OPTINTRO     =  "-"             # Option introducer
+PATHDELUNIX  =  ":"             # Separates include path elements on Unix systems
+PATHDELWIN   =  ";"             # Separates include path elements on Windows systems
+PATHSEP      =  os.path.sep     # File path separator character
 RANGESEP     =  ":"             # Separator for instance ranges
 SINGLEINST   =  "SINGLEINST"    # Indicates a single, not range, replacement instance
 WINDOWSGROUP =  "WindowsGroup"  # Returned on Windows w/o win32all
@@ -1842,6 +1853,15 @@
 
                     # Read the included file, stripping out comments
 
+                    # Use include path if one was provided
+
+                    inclpath = os.getenv(INCLENV)
+                    if inclpath:
+
+                        found = searchpath(inclfile, inclpath, PATHDEL)
+                        if found:
+                            inclfile = found[0]
+
                     try:
                         n = []
                         f = open(inclfile)
@@ -1876,6 +1896,35 @@
 
 
 #####
+# Search Path Looking For Include File
+#####
+
+def searchpath(filename, pathlist, pathdelim):
+
+    # What we'll return if we find nothing
+    
+    retval = []
+
+    # Find all instances of filename in specified paths
+
+    paths = pathlist.split(pathdelim)
+
+    for path in paths:
+
+        if path and path[-1] != PATHSEP:
+            path += PATHSEP
+
+        path += filename
+
+        if os.path.exists(path):
+            retval.append(os.path.realpath(path))
+
+    return retval
+
+# End of 'searchpath()'
+
+
+#####
 # Print Usage Information
 #####
 
@@ -1890,6 +1939,16 @@
 #                    Program Entry Point                   #
 #----------------------------------------------------------#
 
+# Set up proper include path separator
+    
+
+if WINDOWS:
+    PATHDEL = PATHDELWIN
+
+else:
+    PATHDEL = PATHDELUNIX
+
+
 #####
 # Command Line Preprocessing
 #