How to fix superscript issue in obout grid header

Hi,

I am using a obout grid in my project i struct with superscript issue.I need to fix header with super script.I follow the below process to get the result but I am not getting the issue fix

I am getting the result like in below image

so i made the below change the to achive the changes in c#

string headertext = "India®";
grdCampaign.Columns["Country"].HeaderText = "India®";
headertext.Replace("®", "®");

grdCampaign is my grid id

superscript_ table class is this

.superscript_table { font-family: Arial; font-size: 12pt; }

I need to set tread mark as superscript and am using obout grid for my project

The above code is sample code .please help me out.thank you