just make shortcuts of the exe of the games you want and place them all into one folder so mamewah shows all your pc games in one platform. Then just point the rom path to that folder, and make sure that the emulator title is PC.
Pc Games.ini (mamewah v1.62) ###
emulator_title Pc
### List Generation Settings ###
rom_path c:\Where ever you choose
rom_extension lnk
dat_file
nms_file
catver_ini_file
list_generation_method rom_folder
### Execution Settings ###
pre_emulator_app_commandlines
emulator_commandline PC "[rompath]\[name].[romext]"{dosbox}{safelaunch}
post_emulator_app_commandlines
general_app_commandlines
### Artwork Locations ###
artwork_image_paths
movie_preview_path
movie_artwork_no 1
### Screen-Saver Settings ###
enable_music_in_screensaver 1
select_random_game 0
saver_type slideshow
movie_path
movie_fullscreen 1
quit_delay 30
saver_commandline
### Additional Settings ###
music_path
lcd_display_file_path
### Settings used by MAMEWAH ###
current_list 0
l hope this helps.