I'm sorry, it is not a program I made. But I can answer your question. It is not possible to use the portamento in the program. If you are interested in this program, try to take a contact to the author.
NNID: lioops
Official website: http://ncf.harisen.jp/index.html
I don't speak English, so I use google translation to write this comment.
1そうだね プレイ済み