@SEARCH

@SEARCH[filename[,path]]:  Searches for the filename using the PATH 
environment variable or the specified path, appending an extension if one 
isn't specified. 

@SEARCH returns the fully-expanded name of the file including drive, path, 
base name, and extension, or an empty string if a matching file is not 
found.  If wildcards are used in the filename, @SEARCH will search for the 
first file that matches the wildcard specification, and return the drive 
and path for that file plus the wildcard filename (e.g., E:\UTIL\*.COM).