ctsqlConvert() converts data from one given representation to a new type representation.
stype The data type of the source buffer which is being converted.
buffer1 The buffer containing the source data
length1 Length in bytes of data in source buffer
fmt format string to be used for formatting the output if the desired destination data is a character string type. Currently a format string can be specified only if the input is of type TPE_DT_DATE and the output is of type TPE_DT_CHAR.