If you got corel5, then you have probably got corel photo paint as well. There you can open cdr-files as well and save then in whatever format, suitable for a web page. you can also choose the image compression in case you save them as a jpeg. I mean the gif and jpeg exports frm Corel Photo Paint work perfect, I did this for customized backgrounds for our homepage. In case you do nopt have the photo paint prog, try marking all the elements in CDraw (in the cdr-file) and export them as a compuserve-bitmap (.gif) those will also work with the most browsers and you can adjust the resolution of the picture, in case you want to be aware of the disk-capacity, your server has to reserve for the picture, you want people to download.
Hope this helps you, if not or in case I misunderstood your problem, please let me know, to see if I can help anyway.