Set property_path;value Optional. Overrides the configuration of a variable, property, container, log provider, foreach enumerator, ...

Set property_path;value

Optional. Overrides the configuration of a variable, property, container, 
log provider, foreach enumerator, or connection within a package. When 
specified, the /SET option sets the specified propertypath to the value given.
Multiple /SET options can be specified.

The following is an example of executing a package that is provided a variable
with a value.

dtexec /f mypackage.dtsx /set \package.variables[myvariable].Value;myvalue