Hi Sunitha,
I am back on the site after a long time...so got to read your message just now.
I have actually used butternut squash in place of parangikai(yellow pumpkin we get in India) to make "mathan"(thogayal).
May be you can try it with banana squash too, if you would like mathan. I can share mathan recipe if you want.
Refer this site about winter squash...it is said banana squash can be subsituted by butternut squash, pumpkin,etc.
So I assume it applies vice-versa too.
http://www.foodsubs.com/Squash.html