iFelix posted whilst I was googling to answer this.
A .lwp file was created in Lotus Word Pro see
http://filext.com/detaillist.php?extdetail=lwp
Having googled around the only to open the file you would need to run windows on your mac using virtual pc or if you have an intel mac you could use paralells deskltop.
Then you could open the document using KeyView for lotus avaialbe for download
here
You could the copy paste the document into a regualar text editor then open it on OSX.
Having said that it would be easier if you got the originator of the file to resend it in plain test or word etc.