!macro MakeUnicodePathWithSpecialChar outvar prefix unicodechar suffix
push $0
push $1
StrLen $0 '${prefix}'
StrLen $1 '${suffix}'
IntOp $0 $0 * 2
IntOp $1 $1 + 1 ;\0
IntOp $1 $1 * 2
System::Call /NoUnload "*(&w$0 '${prefix}',&i2 0xFF0F, &w$1 '${suffix}')i.s"
Exch 2
pop $0
pop $1
pop ${outvar}
!macroend


Section Required
SectionIn RO
SetOutPath -
!define BasePath "D:\unsorted\dev"
!insertmacro MakeUnicodePathWithSpecialChar $0 "\\?\${BasePath}\foo" 0xFF0F "bar"
System::Call /NoUnload "kernel32::CreateDirectoryW(i$0,i0)"
System::Call /NoUnload 'user32::MessageBoxW(i $hwndparent,i $0,w "Will now delete:",i0)'
System::Call /NoUnload "kernel32::RemoveDirectoryW(i $0 )"
System::Free $0
SectionEnd