enviornment variables

[Abhishek Misra <abhishekm cdac in>]

Hello,

as recomended i tried to set the following enviornment variables.

CPPFLAGS
LDFLAGS
PKG_CONFIG_PATH
LD_LIBRARY_PATH

to my surprise i get error st. command not found

on running printenv or env
the list of variavle,value that i get does not include any of these

on running env CPPFLAGS="xyz"
this variable,value does gets added to the end of the list 
but on running env again , it is again missing from the list

man env says run COMMAND after setting the value 
this too is not improving the situation

please let me know where could the problem lie.

Thank You