If you still have your Works program you should have no problem saving a spreadsheet as an Excel file that can then be opened directly by Calc: most formulae will copy across correctly.
In the case of Works database files I have found an alternative to CSV or RTF routes, which is usual safer if you have many records but relatively few fields, is to copy and paste to a Calc file. Open the Works DB file in List View; click the top left corner to select all; copy and paste into the second row of a new OOo Calc file. Usually you can simply click OK on the Text Import dialog, and all the data will appear without errors, but only as text, in the Calc file. The field headings row, however, will not have been copied across, so you will need to type the required field headings into the empty top row. Once you have the data in a Calc spreadsheet it can readily be imported into a OOo Base table.
When this issue has been resolved, it would help other users of the forum if you add the word - [Solved] - to the Subject line of your 1st post (edit button top right).
OOo 4.0.1 on MS Windows XP MySQL and HSQLDB