You should modify your code as follows:
@gridTotal.GetHtml(
columns : gridTotal.Columns
(
gridTotal.Column(
columnName : "AuditNum",
format: @<a href="@App.PathOrderEdit?AuditNum=@item.AuditNum">@item.AuditNum</a>
),
gridTotal.Column(
columnName : "Status")
)
);