RNA internal standard

[D L Clarke]

Has anyone managed to generate an RNA internal standard
for quantitative RT-PCR without cloning the desired 
fragment into a vector containing a T7 or SP6 RNA
polymerase promoter region? I am interested in trying
a technique that adds a T7 RNA polymerase promoter
sequence onto the upstream PCR primer. Amplification of 
template using this modified primer along with the necessary
downstream primer should generate a cDNA with a T7 RNA
polymerase promoter at its 5' end. Would in vitro 
transcription of this cDNA with a T7 RNA polymerase
work to generate a full length artificial RNA standard?