FILEEXTENSION
Returns the file extension as a string.
Syntax
string FILEEXTENSION(string fileName)
Example
FILEEXTENSION("C:\\mydir\\myfile.ext")
Returns '.ext'.
info
Remember to escape the backslashes in your file path, otherwise your expression will error.
You can also pass the column name that contains the file path into the function instead of having a hard coded path.
For example:
FILEEXTENSION(FilePath)