Quote from hektor:
I dont know if this is the solution for you, but you can use Alexis VWAP formula
http://forum.esignalcentral.com/showthread.php?s=&threadid=12856&highlight=vwap
and export the study value into DDE, simply modifying this code
http://forum.esignalcentral.com/showthread.php?s=&threadid=11243&highlight=export+excel