List.PositionOf of first not null value in a column

Maybe something like this would work?
For the list...

= {null, "", " ", 456, "  ", "Abc"}

= List.PositionOfAny(List.Transform(Source, each Text.Start(Text.From(_), 1)), {"0".."9", "A".."Z", "a".."z"}, Occurrence.First)

Returns position 3 as the result.

Hi Goodkat,

Alternatively you can leverage the optional 4th parameter and provide a comparer function, for example. 

let
    Source = Table.FromValue({" ", null, "", "#(tab)", "FirstValue i=4"}),
    RowsToSkip = List.PositionOf(
        Table.Column(Source, "Value"),
        true,
        Occurrence.First,
        (x as any, y as logical) as logical =>
            let
                s = try Text.Trim(Text.Clean(Text.From(x))) otherwise ""
            in
                (x <> null) and (s <> "") = y
    )
in
    RowsToSkip

Hi Goodkat, if you wish to use your own solution, I've just updated your Position step:

= List.PositionOf(Quelle[Column1], "group", Occurrence.First, (x,y) => Text.StartsWith(x ?? "",y, Comparer.OrdinalIgnoreCase))

...but, if you want to skip rows until "Group" appears I would prefer this:

= Table.Skip(Quelle, each not Text.Contains([Column1] ?? "", "group", Comparer.OrdinalIgnoreCase))