keywords echelon in domain????

[badmaash]

If one of your target keywords is:

x = (keyword1 + keyword2)

So you could buy domain = y + x


but does it mater if you buy:

z = keyword1 + nonkeyword + keyword2

will z still count for x

OR does it have to be in the format:

z = nonkeyword + x


TY

[welkin]

I think it matters but with a lowered weight.