Getting a return value from a stored proc

Hi I'm using a stored proc to generate caseid's and it all works fine except I'm getting strange data when I call the stored proc in the after record added event.
When I execute the stored proc in SQL the result data come back correctly but when done in asprunner I'm getting some strange characters.
Here is my code for the event
string sql = "EXEC pdi_GetCaseNum";

XVar CaseNum = tDAL.CustomQuery(sql);

XVar data = CommonFunctions.db_fetch_array(CaseNum);
this is what I get back in the table "-17-0008,"
In SQL it comes back like this "17-0008"
Anybody have any idea's