copy number calculation from cDNA - (Mar/16/2011 )

I have synthesized my RNA into cDNA and now am trying to do a standard curve for qPCR using cDNA as my standards .
How do I figure out the copy number of my cdna from concentration

Thank

Do you have single-strand cDNA (ssDNA)?, because AFAIK you canot measure RNA-cDNA duplex, there is however way to quantify ssDNA after Rnase H digestion.
But to calculate copy number you need to know the length of your product. If you used total RNA and not in vitro transcribed single transcript with defined length I'm affraid you can't calculate copy number.