You have go space in your file name and if you want to use those filters try smth like this:
MPEG2Source("C:\LovehinaAgain1.d2v")
MPEG2Dec3()
Decomb(1)
and about decomb i think you can set strenght from 0-to smth

i'm not sure you can check it in avisynth documentation there is a nice description for filters in it
Oh and Mpeg2Source might not work try to open your d2v with virtualdubmod and when loading you can test avisynth loading options,but propably it will work with none

so script will look like(directshoweis optional if smth else is working write it instead but if none try every option of loading by re-editing script) or just run it with virtualdubmod and convert firstly to avi wchich wibe easier to work with...
Directshowsource C:\LovehinaAgain1.d2v")
MPEG2Dec3()
Decomb(1)
and about Mpeg2Dec3 i never used it so you can try MPEG2Dec without a number
