Copy and paste a Row and delete certain cells - google-apps-script

Question

I am trying to copy paste a row (A3:S3) to the next free row of my sheet.
This works fine with the following code.
What I am now trying to do is to delete the cells C3-K3.
function copypastescript() {
var reference = 'Definitionstabelle!A2';
var rng = SpreadsheetApp.getActiveSpreadsheet().getRange(reference);
rng.setValue(rng.getValue()+1);
var ss = SpreadsheetApp.getActiveSpreadsheet ();
var ss = SpreadsheetApp.getActiveSpreadsheet ();
var source = ss.getRange ("Definitionstabelle!A3:S3");
var destSheet = ss.getSheetByName("Definitionstabelle");
var values = source.getValues().filter(function(e) {return e.some(function(f) {return f})});
destSheet.getRange(destSheet.getLastRow() + 1, 1, values.length, values[0].length).setValues(values);
}

Answer 1

Answer for Q1:
You want to delete the cells "C3:K3" of the sheet of Definitionstabelle after the values of "A3:S3" are copied.
If my understanding is correct, how about this modification?
Modified script:
Please add the following script after destSheet.getRange(destSheet.getLastRow() + 1, 1, values.length, values[0].length).setValues(values);.
ss.getRange ("Definitionstabelle!C3:K3").clearContent();
or
ss.getRange ("Definitionstabelle!C3:K3").clear();
References:
clearContent()
clear()
If I misunderstood your question and this was not the result you want, I apologize.
Answer for Q2:
some code to copy K3 and paste it into J3 before deleting C3:I3 and K3
You want to copy the value of "K3" to "J3" of the sheet "Definitionstabelle".
You want to copy before the vaues of cells "C3:K3" are deleted.
In your situation, should the copy from "K3" to "J3" be done before the copy of "A3:S3"?
If my understanding is correct how about this modification?
Please put the following script before ss.getRange ("Definitionstabelle!C3:K3").clear();.
Modified script:
function copypastescript() {
var reference = 'Definitionstabelle!A2';
var rng = SpreadsheetApp.getActiveSpreadsheet().getRange(reference);
rng.setValue(rng.getValue()+1);
var ss = SpreadsheetApp.getActiveSpreadsheet ();
var source = ss.getRange ("Definitionstabelle!A3:S3");
var destSheet = ss.getSheetByName("Definitionstabelle");
// Added
destSheet.getRange("K3").copyTo(destSheet.getRange("J3"), {contentsOnly:true}); // or destSheet.getRange("K3").copyTo(destSheet.getRange("J3"))
var values = source.getValues().filter(function(e) {return e.some(function(f) {return f})});
destSheet.getRange(destSheet.getLastRow() + 1, 1, values.length, values[0].length).setValues(values);
// Added
ss.getRange ("Definitionstabelle!C3:K3").clearContent(); // or ss.getRange ("Definitionstabelle!C3:K3").clear()
}
Reference:
copyTo(destination, options)