SSIS derived column expression

Hi,

I have column Vdn in that in SSIS data flow pipeline that has values like 02256, 2256 etc. Firstly, I need to convert ALL the 4 digit Vdn (if any) to 5 digit Vdn by adding 0 ie 02256 in pipeline. Secondly, I need to sum all data columns except MaxOCWTime, MaxWaiting.

Before loading the data into Ole db destination. To convert vdn to 5 digit, I am trying

len(Vdn)==4? "0+[Vdn]"?"[Vdn]" It is not working. Please suggest.

Thanks,

hsbal