You see, this is another problem with this crowd.
NOBODY can give a straight-forward answer around here.
"command-line-options" - proper answer to your question
To turn on coin-control
[click] SETTING
[click] OPTIONS
[click] WALLET
[check-mark] Enable coin-control features
[click] OK
[click] SEND
[click] Inputs...
[right-click (the funds you choose to LOCK or UNLOCK)]
[click] Lock unspent
or
[click] Unlock unspent
If you've already completed your task, good for you.
I'll never understand WHY you people can't just give somebody a straight-forward answer, especially for something so DAMN SIMPLE.
Pathetic !
Sure, the links are good but ANSWER THE QUESTION !
I would love too...but I don't have these answers. I use Slawek to manage my Masternodes...and he patiently walks me through all this stuff. I'd love to be more helpful here

EDIT: Most of the people that do help are on DT. No excuse of course. Its something I've found challenging too when I've needed a hand. But most peeps stay the hell out of here because its full of noobs like me.