I dug out a DVD I had of my personal Word documents from several years ago and found some info that may be helpful:
There is a program out there called dbxtract.exe. You should be able to find it easily with Google. I DO NOT KNOW IF IT WORKS OK ON WINDOWS 7. You would then have to import the EML files it makes into WLM. EML files may be more appetizing to WLM's import function.
I used it at one time and made a Word doc about it. Here are some excerpts from that Word doc:
DBXtract.exe extracts all mail and news messages from individual dbx files.
Be sure OE is shut down when you run it. THIS IS VERY IMPORTANT. Choose c temp or something for a destination folder.
Files are extracted with an eml extension, which when poked opens up outlook express and displays them. Once extracted, the individual messages can then be poked, which opens outlook express. The files can then be forwarded or moved as normal.
The program works by reading the location of the data message stores from the Registry and then loading those into the Path combo box. It then searches the path and loads the dbx filenames that are present in that path into the File com-bo box.
Messages can be extracted with two different file naming procedures. The de-fault (By Subject) names the files by the subject of the message (with all punctu-ation removed). Choosing the By Prefix option, allows one to specify a prefix in the text box and then all files are extracted using that prefix rather than using the message subject. With both procedures, duplicate filenames are appended with a number (e.g. filename(2)). Messages are extracted in the order they appear in the dbx file, which may be totally unrelated to the temporal sequence of the messages.
The program automatically distinguishes between news and mail messages and names the files accordingly with the respective nws and eml file extensions. It also extracts messages completely intact, be they plain text messages with at-tachments or HTML messages.