You could find this at a salvage yard easily and cheaply. There are salvage yards within driving distance of most towns.
The latch is broken or out of adjustment.
If the trunk on a Honda Civic will not close the locking mechanism may be jammed. Be sure to remove any obstructions on inside the trunk latch. If the latch is broken replace it.
A Honda Civic hood latch is usually located underneath the dashboard on the left of the driver. In some models, it may be located on the floor by the drivers seat.
According to the following link (http://www.honda.com/newsandviews/article.aspx?id=2003112036818), LATCH was put into Honda Civics starting with the 2001 series.
The latch itself is held on with bolts, easy enough to change. The release cable has to be fed down the inside of the rocker panel and into the trunk.
The only way i can think of would be to remove your bumper so you can get to the latch, and either unbolt the latch from the core support or unbolt it from the hood...
go through the grill and use a heavy duty screwdriver to pry back the latch
just push up a bit the latch on the trunk. may need to wedge it to keep it there
The reason is because the cable connecting to the latch has already been over stretched. Changing a new cable should rectify your problem.
The child safety lock is engaged. Disengage it on the door next to the latch.
Take it to the body shop. They have to open the hoods when they are wrecked.
With a pair of pliers pulling the latch.