Power Plan 64 is a very capable spreadsheet for the Commodore 64 as can be seen by the manual which is over 200 pages.  There's a nice article in the November issue of Compute's Gazette (Issue 29, page 29) titled "Anatom of a Spreadsheet" you should check out if you're interested in reading more about the available spreadsheets for the C64.

Big thanks to Raj, one of our visitors, that shared a .g64 image (all protection in tact) of this program.  I've been unable to find a version with the protection removed, so if you have an unprotected copy and would like to share, please use the Contact Us link to get in touch.