Allow to manually setting the search register

[Loric Brevet]

That would be useful to be able to set the search register manually.

For example, let's say I have this text:

// special command to search hello
3j"/ywn

// prompt
hello

... // lots of code

function helloworld() {
    // core of my function
}

If "/yw would work, executing @; on line with 3j"/ywn would automatically set the current search term to "hello" (or whatever is under my prompt line), and the n would jump to the actual search result.

It seems that the search register in only one-way for now. You can paste the last searched keyword, but not manually define the current keyword to search.