orderClause with Advanced criteria value

Hi,

We are using:
a)SmartGWT Version: 5.0p

b) Tested using IE Version: 11
c) GWT 2.6.0

Problem:

Using advanced criteria value in <orderClause>.

<operationBinding operationType="fetch">
<orderClause>$advancedCriteria.sortOption</orderClause>
</operationBinding>

In my client class I am passing the value for sortOption:

AdvancedCriteria advCriteria= new AdvancedCriteria(OperatorId.AND);
advCriteria.addCriteria("sortOption","COLUMN1 ASC, COLUMN2 DESC");

when I run this the sort option coming with single quote in the sql query order by clause, so the order by is not working as expected.

sample sql output:

select column1, column2,.. from TABLE1 order by 'COLUMN1 ASC, COLUMN2 DESC'

Could you please help me.