Add the following line at the beginning of the expert. This will allow you to enter a comment on the expert's Input tab.

static input string Order_Comment = ""; // Custom order comment

Set the EA to attach the comment to a position. You have to modify the OpenPosition function. There are two ways:

Variant 1.  replace the default comment (the EA's magic number)

// Replace

 string comment    = IntegerToString(Magic_Number);

// with

      string comment    = Order_Comment;

Variant 2. Add your custom comment to the EA's magic number:

string comment    = IntegerToString(Magic_Number) + ' ' + Order_Comment;

Hello,
1. I managed to create the field in the expert input tab, tha is o.k.
But it still does not show in the comment (Kommentar)-field when running in MT4.
(Only as long as I put the cursor over the empty field, it shows the order number and the EA-ID)

2. I do not know how to modify (Variant 1 or 2) the "OpenPosition" because in my EA-Studio created EA it looks completely different to the example in your suggestion.

3. In the EA's created with FSB I found only one "Order_Comment" line, but there it works and is shown in the Kommentar-line.

Do you have an idea what I am miss, maybe it is not as easy as I thought