Everything you need to know about OnTime procedures (but were afraid to ask):
http://www.cpearson.com/excel/ontime.htm
You'll need to have excel running for this to work.
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Some versions of windows have scheduler programs. (Or you can get a
freeware/shareware version on the web (
www.shareware.com is where I look first.)
Then you could have that scheduling program start an excel workbook. If you
name the macro Aut

pen, then it'll run when the workbook opens.
(But your pc will have to be on <vbg> for that to work!)