With audiograbber, click on the MP3 settings button, and make sure you choose the external encoder tab. Tell it where the lame executable sits, and ensure that the settings are set as 'user defined' (it automatically defaults to 128kbps which is not what you want). There should be a box allowing you to specify any settings which should only have %s and %d in it, after this type in your settings, e.g. you want standard (VBR @200kbps) then the box should look like this:
%s %d --alt-preset standard