Dear R and R com user.... I have the following matlab which acesses a com server, code which I am trying to translate to R using the Rcom package: clear all; clear analysis; analysis = actxserver('EDAL.MSAnalysis'); analysis.Open('E:\work\ChromPeakFinderdata\DatafromKlaus\E112L-cad13-PI-24h_pos_1-C,3_01_2562.d'); specCol = analysis.MSSpectrumCollection; count = specCol.get('Count'); This is how far I got... rm(analysis) analysis <- comCreateObject("EDAL.MSAnalysis") comGetObjectInfo(analysis) comInvoke(analysis,"open","E:\work\ChromPeakFinderdata\DatafromKlaus\E112L-cad13-PI-24h_pos_1-C,3_01_2562.d") specCol <- analysis$"MSSpectrumCollection"> specColfunction (...) comInvoke(handle, ..FUN, ...) <environment: 0x022a4734>> comInvoke(specCol,"get","Count")NULL Seems to be the wrong track ... What would be the equivalent of analysis.Open('E:\work\ChromPeakFinderdata\DatafromKlaus\E112L-cad13-PI-24h_pos_1-C,3_01_2562.d'); specCol = analysis.MSSpectrumCollection; or of count = specCol.get('Count'); in Rcom? Help is highly appreciated... best wishes Eryk