How to make pumpkin extract
The pumpkin flavor you're likely looking for is nothing more than the spices that are added to pumpkin "stuff": cinnamon, nutmeg, cloves, etc. If you attempt to do an extract to achieve "pumpkin essence", you will not be happy with the results.

I have been a home brewer (beer, wine, mead, etc.) for 20+ years and have seen many attempts from various brewers to make a "pumpkin beer".  Long story short (and you can do a search and verify what I'm saying on any beer brewing forum's out there), it's the spices that make the flavor, not the pumpkin squash fruit.

Bottom line is there is no "typical anticipated pumpkin flavor" imparted by just pumpkin. To make a great pumpkin beer, the guys who have made multiple batches of pumpkin beer using varied recipes (using chunked up pumpkin, cooked pumpkin, roasted pumpkin, etc.), all ended up finding the perfect pumpkin beer was made using only the spices and not even using any pumpkin at all.