Question: I watched some videos about implementing IRenderingModel interface and inherit renderingModel class in order to use Sitecore data template fields in MVC models (like <https://www.youtube.com/watch?v=dW_rQp9bMmE&index=2&list=PL1jJVFm_lGnweAZ0jF1SgfooRv3h9jiEY> )
but as far as I understood, in MVC side, all properties are declared as HtmlString; hence I'm looking for an effective way to use Sitecore fields in MVC model

Below are defined data templates:

News
----

Title Text  

Description RichText  

Image Image  

Category MultiList 

Category
--------

Title Text  

ID Int

Answer: 
As commented, there is no need to convert so much between string, character, integer and string again... just get the integer value of each character and compare it to your range values. You can write integer constants in hex form with `&H` prefix.

```
Dim inTexts = "abc豈あああ"
For Each c As Char In inTexts
    Dim v = AscW(c)
    If v < &HF900 OrElse v > &HFAFF Then
        Console.Write("Character is out of range: ")
    Else
        Console.Write("Character is inside range: ")
    End If
    Console.WriteLine(c)
Next

```
This is my answer:

```
Dim i As Integer  

Dim tmpChr As String
    toUniCodeHex = ""
    Dim iStart = Convert.ToInt32("F900", 16)
    Dim iEnd = Convert.ToInt32("FAFF", 16)
    For i = 0 To Len(inTexts) - 1
        'tmpChr = Convert.ToString(AscW(inTexts.Substring(i, 1)), 16)
        tmpChr = AscW(inTexts.Substring(i, 1)).ToString("x4")
        Dim v As Integer = Convert.ToInt32(tmpChr, 16)
        If v < iStart Or v > iEnd Then
           *'not bettween.*
        End If

    Next

```