If you are running v2000 or later, and if the text is actually within the tables, in the correct field types (see manual or online help) then you can use SQL Server for full text searching.
However, if the items are held in binary form (eg as .pdf files within a binary BLOb) or held outside the database, then you will not be able to search within them.
Instead, try getting someone to create a program that reads these external documents and creates an index for you. The index can then be held within SQL Server and accessed there ...