If you are using the default.stp file, it ignores numbers. You can create a special stp file for use with this database that includes numbers. Just remove the line:
If you are looking for numbers in a Number field, numeric fields have to be searched for by specifying this formula in the search window (or by using a Form to search which generates this formula):
Punctuation and other special marks, except for '&', "/", ":", and "." are NOT included in the index so there is no way to search for them. You can never find "C++" no matter how you arrange your query since it isn't "text" and it is not included in the index. You'll have to use the non-indexed search function by holding down <shift> as you click on the flashlight icon. This will bring up the regular search dialog box. Type C++ in there and let it search all documents. When finished, select "Show only selected" under the View menu and you'll see all the documents that contain "C++" in them. Keep in mind the words won't be hilighted like in the FTS, but at least you can identify all the documents.