I've never used Works, so I can't say for sure, but according to this Microsoft knowledge base article you should be able to save your Works calendar data in "vCal" format, which iCal can import.
Start Works Calendar.
On the File menu, point to Export, and then click vCalendar.
Under Range, enter the date range for the information you want to export.
Under Include, select the appointments you want to export.
Click OK.
In the Save in box, click to select the location where you want to save the file.
In the File name box, type a file name for the Calendar information, and then click Save.
You should then be able to transfer that file to your Mac and just drag it onto iCal.