Running BASH commands from a variable

Shell Programming and Scripting
1

I am trying to assign a command to a variable and use it. I have tried every possible quoting variation except the correct one. :confused: Here is an example:

CMD="grep description $i | grep "::""
$CMD | nawk ...

Thanks in advance for you help.

2 
CMD="grep description $i | grep "::""
eval $CMD | nawk ...