I totally agree Pat. Even though Pascal is verbose compared to Python and doesn't have the same community support or external libraries, it requires special knowledge to understand the syntax.
Anyway thanks to you I figured a way to do it, though it only works with files in metric units. If you draw a Space, leave it selected the run this script, you will see the desired criteria string:
perimValueStr = vs.GetRField( vs.FSActLayer(), 'Space', 'Perim' )
(Flag, perimValue) = vs.ValidNumStr(perimValueStr) #convert notation string to real number
perimValueStr = format(perimValue, '.4f') #convert real back to string to 4 decimal places
crit_ = "('Space', 'Perim' = "+ perimValueStr + ")"
vs.Message(crit_)