I need to reconfigure summary plugin after grid reconfigure. Can anyone let me know how to do the reconfiguring of summary plugin after grid reconfigure

below is the reconfig code.
var GRIDCM = new Ext.grid.ColumnModel({
defaults: {
width: 120,
sortable: true
},
columns: [{dataIndex: 'start_date',header: 'Start Date',width: 100, align: 'left', tp:'string',renderer:Ext.util.Format.dateRenderer('m/d/Y')},
{dataIndex: 'end_date',header: 'End Date',width: 100, align: 'left', tp:'string',renderer:Ext.util.Format.dateRenderer('m/d/Y')},
{dataIndex: 'Status',header: 'Status',width: 100, align: 'left', tp:'string'},
{dataIndex: 'eom_booked',header: 'EOM Booked',width: 100,align: 'right', renderer: usMoneyWODecimalNFT, tp:'decimal',summaryType: 'sum'},
{dataIndex: 'mtd_ama',header: 'MTD AMA',width: 100,align: 'right', renderer: usMoneyWODecimalNFT, tp:'decimal',summaryType: 'sum'},]
});
this.NFTGrid.reconfigure(this.NFTGridStore, GRIDCM);

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Thanks & Regards
Hari