Hello, World!

i'm only using assembly in my toy OS project, (not trying to be a badass or anything, i just think it's a fun way to learn 32 bit assembly coming from the 16 bit world of the 8086) and i'm working on my IDT now, so i have something like this for each entry:

i'd like to have the offset initialized when i assemble it rather than write it in as it runs, like this:

but the upper and lower words are split all topsy-turvy like. Reading through the NASM manual, it seems like what i want are the >> and & operators, but when i try

NASM spits it back out saying "shift operator may only be applied to scalar values."

Kinda long post, but my question is this:
How can i initialize data using only the upper or lower word of an address?

Sorry to double post, but...

i figured out that i did not want to initialize my IDT when i assembled it, as then i would have to initialize the entire IDT or mess around with the linker script to get another uninitialized section to go right after it which i would then have to fill with zeros anyway.

But if anyone knows how to extract the upper and lower words of addresses to initialize parts of data like that, i would still like to know how since it might be useful sometime.