Hi Alan
you can put Workbook_Open code against the ThisWorkbook module
(right mouse click on a sheet tab, choose view code ... look for the
workbook name in bold on top left - choose view / project explorer if you
can't see it... under the workbook name you'll see ThisWorkbook - double
click on it ... on drop down on left hand side of white paper on right hand
side of screen choose Workbook .. )
which will fire when the workbook opens (as long as macros are enabled or
security set to low (not recommended)) ... you can then open this workbook
from a command line, e.g.
excel.exe c:\temp\mybook.xls
Hope this helps
Regards
JulieD