setting a shell script variable in awk

The following is part of a larger shell script

grep -v "Col1" my_test.log | grep -v "-" | awk  '$5 == "Y" {print $1}' 

instead of printing, can I set set $1 to a variable that the rest of the shell script can read?

if $5 == Y, I want to call another shell script and pass $1 as a variable.

Such that...
I assign variable parm to the result of a calculation
Show that it is set
Then print out that "6th" column in an awk statement
*Note that I set col (within awk) to be equal to variable parm

$ parm=$(ls sample*.txt | wc -l)

$ echo $parm
6

$ head sample3.txt | awk -v col=$parm '{print $col}'
46.6432798439
48.8478948517
45.8022601455
48.780669145
47.7312017846
41.7389244255
54.1498530714
X
41.709838673
41.4599808018

Are you trying to do something like this?
Without seeing your file(s), it is hard to understand what you are trying to do.

If you use awk instead of grep then you can set $1 into a local variable:

new_var=$(awk '!/Col1/ && !/-/ && $5=="Y"{print $1}' my_test.log)