How to determine if string contains specific substring within the first X characters

Question

I want to check whether Value1 below contains \"abc\" within the first X characters. How would you check this with an if statement?

Answer 1

Adding on from the answer below i have created this method:

    public static bool ContainsInvalidStrings(IList invalidStrings,string stringToCheck)
    {

        foreach (string invalidString in invalidStrings)
        {
            var index = stringToCheck.IndexOf(invalidString, StringComparison.InvariantCultureIgnoreCase);
            if (index != -1)
            {
                return true;
            }
        }
        return false;
    }

it can be used like this:

            var unsupportedTypes = new List()
        {
            "POINT Empty",
            "MULTIPOINT",
            "MULTILINESTRING",
            "MULTIPOLYGON",
            "GEOMETRYCOLLECTION",
            "CIRCULARSTRING",
            "COMPOUNDCURVE",
            "CURVEPOLYGON",
            "MULTICURVE",
            "TRIANGLE",
            "TIN",
            "POLYHEDRALSURFACE"
        };


            bool hasInvalidValues =   ContainsInvalidStrings(unsupportedTypes,possibleWKT);

you can check for multiple invalid values this way.