Decimal in a string to Char in String problem

Good day. I am facing a problem. I am using Visual Studio C++ and wish to create a Window Form Application. The purpose to create this program is to show the encrypted text from a textbox in a small window.

Below is my code:

String^Data1;String^Data2;int key ='x';Data= richTextBox1 ->Text;int iLen = richTextBox1 ->Text->Length;//define the string lengthfor(int i=0; i < iLen ; i++){Data1+=Data[i]^(int(key)* i +int(key)/(i+1))%255;//Encryption formula}MessageBox::Show(Data1);//Show the encrypted text in window

For above, if Data din't pass the Encryption Formula, i will show the exactly TEXT in the textbox. But Data undergo the encryption formula, The DATA1 show the TEXT in decimal value.

As example:

"1"=49

When i type "1", undergo the formula, so it must come out "I" in character form. But from my code above, it show decimal 73(decimal of char "I").

How can i make it to show "I" rather than showing 73?

Thanks in advance. Sorry for my bad English and Explanation.