Try checking out to see if you have any race car builders in your town. They can fab up a line using either a hard metal line or braided stainless, I prefer braided stainless. I had to fab my own lines on my Chevy powered Jeep project, and I used braided for the durability and flexiblity. I bought the supplies from online and had a race car shop make the line.
If it is just a hole in the hose, you could cut it and splice it
with a 3/8" hose splicer (cheap anywhere)
If its at the crimp, you could remove the hose assembly and
cut apart the crimped ring on each end of the bad hose and replace
it with 3/8" tranny cooler hose (at all parts stores) and hose clamp it down,
then reinstall the hose assembly.