How would I download and use the U44 Test Build on Technic? could someone help me out on this?

You can edit the modpack folder:

Roaming\.technic\modpacks\<Modpack>\mods

Or not use technic xP Just use Forge 

The test builds are only for Beta Testers like you, hence they are not on the Technic launcher, which is public.

Try downloading the Beta product as usual, (from the Beta products page), then drag it into your Roaming\.technic\modpacks\\mods 

as Starlord2001 stated.