Update Group Description to HTML via PowerShell

I am using the following code/function to add groups to a site (SP-2010):

function Create-SPGroupInWeb 
{  
    param ($url, $groupName, $permissionLevel, $description)  
    try{
        $web = Get-SPWeb -Identity $url
        if($web -ne $null){
            if ($web.SiteGroups[$groupName] -ne $null)  
            {  
                write-Host -f red "Group $groupName already exists!"
            }  
            else  
            {  
                $web.SiteGroups.Add($groupName, $web.Site.Owner, $web.Site.Owner, $description)  
                $group = $web.SiteGroups[$groupName]  
                $roleAssignment = new-object Microsoft.SharePoint.SPRoleAssignment($group)  
                $roleDefinition = $web.Site.RootWeb.RoleDefinitions[$permissionLevel]  
                $roleAssignment.RoleDefinitionBindings.Add($roleDefinition)  
                $web.RoleAssignments.Add($roleAssignment)  
                $web.Update()
                write-Host "Group $groupName created successfully"
            }  

            $web.Dispose() 
        }
    }
    catch [System.Exception]
    {
        write-host -f red $_.Exception.ToString()
    }
}


Create-SPGroupInWeb -url "http://my-webApp:port/" -groupName "New Group" -permissionLevel "Read" -description "My New Group Description - <STRONG><U>Branch Manager</U>&nbsp;<FONT 
color=#ff0000>ONLY</FONT><FONT color=#000000>!!</FONT></STRONG>"

Taken From: Create Site Permission Groups and Add Users for SharePoint - Powershell

This all works 100%

The problem is, is that the "Description" gets added as plain text.
After visiting numerous sites and blogs with tons of methods, nothing has worked!

Question: How do I get it to accept/compile/convert to HTML View?

The Process:

I have an Excel document with a couple hundred Users, Branch Managers, H/O Users, RM's, also various Chains and the Branches under them, etc... which end up in the thousands.

So I take the Excel document provided by Business and use it as is with a few added Sheets with scripts and formulas to pull the required details to "compile" my script as used in the last command in the code above.

I then copy all the rows with the compiled code / "Command" and run it in my PS Script. As mentioned above this works!

It's only the HTML part that I am struggling with.

NB: I'm not new to scripting, but PowerShell and SharePoint is very different to what I'm used to, so please be specific and detailed with your help. :)