neither loadmap nor mapimp plugin is working for loading the mfc100 symbol info form IDA to olldbg. however, there is
a different way to make it work. get a copy of mfc100.lib from vs2010, and put it somewhere in your olldbg folder. start your app using olldbg, and then click the menu-->debug-->select symbol path (i.e. the path where mfc100.lib). after you have set the path for the file, you can click "select imported lib" from the debug menu again, add mfc100 into the lib list, and then click "process". restart your app using olldbg, all symbol info for mfc100 dll can be loaded into your app.
sorry, my ollydbg is in chinese