Doing $woo + $hoo does not return the proper filepath:

PS > $woo = "c:\temp"
PS > $hoo = "shabang"
PS > $woo + $hoo
c:\tempshabang
PS >

Instead, you should use the Join-Path cmdlet to concatenate $woo and $hoo:

New-Item -ItemType File (Join-Path $woo $hoo)

See a demonstration below:

PS > $woo = "c:\temp"
PS > $hoo = "shabang"
PS > Join-Path $woo $hoo
c:\temp\shabang
PS >