I don't have that compiler, as I have decided to stop handing Microsoft money every time they bring out a new operating system or compiler every couple of years, however I can guide you in the right direction, I think.
The .dsp files are not that confusing or magical, if you edit one in a text editor (eg. Notepad) you will see lines like this:
SOURCE=.\doc.cpp
# End Source File
# Begin Source File
SOURCE=.\doc_construct.cpp
# End Source File
# Begin Source File
SOURCE=.\documentation.cpp
# End Source File
# Begin Source File
This is from another project, but it is the general idea.
Now, what you can do is use this to get a list of files that are in the project, in this case:
doc.cpp
doc_construct.cpp
documentation.cpp
Then, start a new blank project and just add in the files you see in that list. This should give you a pretty good basis for getting a compile to work.