First, create the .def file from the DLL itself:
#> /usr/bin/impgen WINSCARD.DLL > winscard.def
Then, create the .a import library:
#> /usr/bin/dlltool --as=as \
#> --dllname WINSCARD.DLL --def winscard.def \
#> --kill-at --output-lib libwinscard.a
Now you can place libwinscard.a into a standard library path and use -lwinscard to link using it. Note that this file is only required to be found by gcc when linking. It will not be required when executing the program.