problem in creating web API where data is driven from expression rule

Hi,

I am new to appian .I created a web API to download csv template using expression rule where expression rule is fetching data from  data store point.

Here i am facing problem for setting rule data in web API.

Please find the code below

a!localVariables(
local!pagingInfo: a!pagingInfo(startIndex: 1, batchSize: -1),
local!excelData :rule!SBA_GetAbsenceDataForCSV(rule!SBA_GETALLAbsencseType(local!pagingInfo).data),

/*
* Construct an HTTP response that contains the information that we just stored
* in 'local!user'.
*/
a!httpResponse(
/*
* Set an HTTP header that tells the client that the body of the response
* will be a CSV attachment.
*/
headers: {
a!httpHeader(
name: "Content-Disposition",
value: "attachment; filename=Mytest.csv"
)
},
/*
* Create a CSV value of 'local!user' and place it in the response body.
*/
body: {
"Id,AbsenceType,Points,Incentie,Active,CreatedBy,CreationDate,UpdatedBy,UpdationDate,ProcessedDate" & char(10) &
local!excelData-----------------------------------here i am facing problem it is not treating it as aarray of rows

}
)
)

any suggestion on it will be really appreciable.

Thanks in Advance.