How to create a rounded rectangle for Drop Caps?

1 click!

// by FRIdNGE, Michel Allio [06/04/2023]

// TO BE PREVIOUSLY CREATED BEFORE LAUNCHING THE SCRIPT:

// "DropCap" Para Style, including the following Grep Style: appliedCharacterStyle = "DropCap", grepExpression = "^~a."
// "DropCap" Char Style (see Grep Style)

// "DropCap" Object Style
// "DropCapLetter" Para Style

app.doScript("main()", ScriptLanguage.javascript, undefined, UndoModes.FAST_ENTIRE_SCRIPT, 'DropCap! …"');
  
function main() {
    var myDoc = app.activeDocument;
    var myParagraphStyles = myDoc.allParagraphStyles;
        for ( var s = 0; s < myParagraphStyles.length; s++ ) if ( myParagraphStyles[s].name == "DropCap" ) var myParaStyle = myParagraphStyles[s];
    var myObjectStyles = myDoc.allObjectStyles;
        for ( var s = 0; s < myObjectStyles.length; s++ ) if ( myObjectStyles[s].name == "DropCap" ) var myObjectStyle = myObjectStyles[s];
    app.findGrepPreferences = app.changeGrepPreferences = null;
    app.findGrepPreferences.findWhat = "^~a?(.)";
    app.findGrepPreferences.appliedParagraphStyle = myParaStyle;
    app.changeGrepPreferences.changeTo = "$1";
    myDropCaps = myDoc.changeGrep();
    app.findGrepPreferences = app.changeGrepPreferences = null;
    for ( var i = myDropCaps.length-1; i >= 0; i--) {    
        var myDropCapFrame = myDropCaps[i].insertionPoints[0].textFrames.add();  
        myDropCapFrame.contents = myDropCaps[i].contents;  
        myDropCapFrame.applyObjectStyle (myObjectStyle);
        myDropCapFrame.clearObjectStyleOverrides();
    }
    alert("Done By FRIdNGE! …")
}

(^/)  The Jedi

I don't think that can be done with any combination of 'live' styles that would adapt to the text the way a drop cap does.

Either a graphic image (of each needed letter in a rectangle), sized and floated to the left, or possibly a text box with rounded corners and the letter inside, also floated left, will be needed, unless I'm missing something.

Unfortunately, I couldn't find "edit" option for my first message. I think I have to add more details about my process.

I used the "Drop Caps" feature for the first letter "E"
Then I added a stroke from Underline Options to create a rectangle background and 
But I couldn't find a way to get the result I posted in the image above.