radiator overflow tank question

So I have to move my overflow bottle to fit my FMIC and slam panel. I have done some searching on some threads and have found what i thought to be true- ie -coolant flows into the overflow tank when radiator/ engine is hot and returns/ is sucked back into the radiator by vacuum when radiator/ engine cools- which is why the drain line between radiator and overflow neeeds to be submerged in coolant inside the overflow tank -which brings me to my question - but first - I have bought a catch can I am planning on modifying into a coolant bottle (keep in mind I know it is probably too small for a standard radiator overflow bottle however I have a godspeed radiator on order which if my calculations are correct should only need a small overflow - about 40-50% smaller- I can test this anyway and will find out one way or another).Picture of catch can I am planning to use as coolant overflow bottle:

So my question is can someone tell me how to modify this can so the line from the radiator into the can is continued inside the can to the bottom as in my diagram (with this in mind this is why i bought a can that the top unscrews from):

I figure the only options I have are find a rubber grommet and just have the hose inserted into the can to the apropriate level (dodgy in my book) or figure a way I can have a fitting on both sides and then have a length of hose inside at apropriate length OR lastly have a aluminium straw type thing welded onto the inside of the apropriate line to the correct length.

Anyone have any other ideas or know of any double ended threaded fittings I could use?

.. and yes I realise I will have to block the drain at the bottom of the catch can with a bung...

any ideas, input or links to magical double ended barb fittings with threaded centres appreciated...

You dont acutally need to move the overflow bottle , I fittted my fmic but made custom brackets to move the the intercooler so its a very nice tight fit to the back of the top secret bumper mouth,otherwise you end up with a couple of inches from the mouth of the bumper and the core saves doing any ducting shown in this thread http://www.mkivsupra.net/vbb/attachment.php?attachmentid=82056&d=1221568108

heres a pic.

Its not just the FMIC its the slam panel that will need the bottle moved- and I have a stock bumper with seibon lip also so it will poke out the bottom if I mount it like that- but much thanks for the response!

Ah got you no worries,

Its not just the FMIC its the slam panel that will need the bottle moved- and I have a stock bumper with seibon lip also so it will poke out the bottom if I mount it like that- but much thanks for the response!