Greeting, everyone! I am a user of R and Bioconductor from China, and now encountered a severe problem these days. I have some experimental data from affymatrix gene-chip, which is in Microsoft excel format (.xls). And I'd like to convert them into eset class object in R environment. So I downloaded the bioconductor excel plug-in supplied by your website, and install the macro as well as the R (D)COM server including the RExcel plug-in, and R (version 2.2.1) and Bioconductor modules Biobase (including vsn). After finishing all of these, I modified a .xls into the required format described in the file "ExprSetBuilder Excel addin.doc", and applied the macro to all of my data. However, an odd error occurred when I tried to apply the macro supplied in you excel plug-in package. The prompted message displayed in the Microsoft Visual Basic Editor said that "can not find the method or data element". (This was translated from Chinese by myself for the language of my windows system is Chinese). And the highlighted error region was 'If Not RInterface.REvalReturn("require(Biobase)") Then', in which the word REvalReturn was highlighted. So why this happened? Which package and/or software do I need to install to solve this problem? Thank you very much! And very eager to get your reply here! Best wishes! Sincerely yours User from China