Yipieee!!!
I think my problem is solved ! Thanks to SuicideJunkie & jrsimmon.

#     this code works perfect and returns 0 or 1
my $isErased = $worksheet->Cells(1,2)->Font->{'Strikethrough'};

#     but using 'Strikeover' in the code
my $isErased = $worksheet->Cells(1,2)->Font->{'Strikeover'};
#     causes the following ugly error message:
# Win32::OLE(0.1707) error 0x80020003: "Member not found"
#    in METHOD/PROPERTYGET "Strikeover" at FONT-test.pl line 24
[download]

Yesterday -at work- I already tried this wrong coding and had no more idea how to proceed.

Here -at home- on my laptop, I have an English Excel-Version,
which showed me the right wording, when I "wiped" the text in cel(1,2).
But at work, we have German versions of M$-office, showing 'Durchgestrichen'. grrrrr......

Have I nice WE!