The spaces in the path should not be an issue when unzipping. Here is the example I used from my site with the paths I used. The source and destination path both had spaces, as did the two filenames in the ZIP file I used.
proc main
string sPWZipPath, sCmdLine, sTargetPath, sZipName, sSourceFile
integer iRunTaskID
sZipName = "PWZIP.EXE"
sPWZipPath = $PWTASKPATH ;Setup the needed paths
sTargetPath = "e:\program files" ;Path to unzip ZIP contents to
sSourceFile = "c:\program files\test one.zip" ;Source ZIP file
addfilename sPWZipPath sZipName ;Build the execute statement
strfmt sCmdLine "%s %s`x01 %s`x01 -o" sPWZipPath sSourceFile sTargetPath
run sCmdLine iRunTaskID ;Run PWZIP
while taskexists iRunTaskID ;Wait for PWZIP to finish
yield
endwhile
endproc
aspect@aspectscripting.com