Finding index in string

private int FindPositionIndexOf(string textForSearch, char characterToFind, int position)
        {
            int indx = -1;
            for (int i = 0; i < position; i++)
            {
                 indx = textForSearch.IndexOf(characterToFind, indx + 1);
                 if (indx == -1)
                     break;
            }
            return indx;
        }