[BioC] Get gene expression data by averaging probes corresponding to the gene?

[697820169]

I am trying to do a pooled microarray analyze with arrays 
of different platform. In order to have a comparable data, 
I have come to the idea to convert the probes in each array
 to corresponding gene symbols, and use these gene expression 
data instead of probe expression as the data to analyze.

I've tried to find a function of averaging probes to 
corresponding genes, but found nothing that meet my need. 
I have done a few google searches like "bioc average probe 
intensity to gene", "bioconductor average probe to gene", 
etc... and came up with no usable information.

If anyone can give me a hint where I can find the function I 
need, I will very much appreciate.

--==Mailed via NDMCTSGH Webmail==--