Dynamic selection of columns in report and print the output

Question

Hi,
I tried to have dynamic selection of columns in SQL query using lexical parameter. The hitch is how to print those selected column in excel ouput ?
Suppose
I have select &col from table_name
Initial value of &col is col1 and in data layout only col1 appears
where &col was replaced with more than a column (col1,col2,col3)
now how to print the column selected at the run time,
i have coded in Before Report Trigger
:cell_val := ' <td><rw:field id:"cl1" src="col1"></rw:field></td>
<td><rw:field id:"cl2" src="col2"></rw:field></td>
<td><rw:field id:"cl3" src="col3"></rw:field></td> ' ;
and this user parameter was replaced in web source using JSP expression
<rw:getvalue id: "v_cell" src:"cell_val"></rw:getvalue>
<rw:foreach src:"g_val">
<table>
<tr>
<% =v_cell%>
</tr>
</table>
</rw:foreach>
but in the output i can see only blank columns
Regards
Suresh

Answer 1

The strings replaced by expression <%= v_cell %>
should print the field values contained in col1,col2,col3 columns, but nothing is printed . i think the custom tags (rw...) are not replaced by the jsp expression properly.