When you set the LeftHeader property of the PageSetup object, you can apply
bold styles by adding special formatters.
F.i.: ActiveSheet.PageSetup.LeftHeader = "Dit is &Ueen test&U" & Chr(10) &
"Pagina: &P".

In VBA this works regardless which language version of Excel you have
installed.

However when I call this from an external application through its OLE
interface, then it does matter which language version of Excel you have
installed!

On a Dutch installation &U is ignored, it needs to be &O (= onderstrepen)
and on a German version of Excel it will display the time two times, as &U
stands for 'Uhrzeit'. The help of these installation contains two tables one
for headers entered by VBA and headers entered manually. It appears that if
you try to set headers and footers in Excel from an external application you
need to use these 'manual' tables.

Is there a way to force Excel to interpret these format codes the same way
when called from VBA?

I am also wandering how it is possible that there is a difference between
VBA and an external app, as both will communicate through the OLE interface
which cannot determine from which environment it was called? Is there
perhaps some preprocessor at work that translates these values in a
transparent way when calling into Excel?

Kind regards,

Danny.