thanks for your help.
I've figured it out at last.
variable set integer %N1%=1
text type :%T%N1%%
it would be useful a little when we are making a dynamic macro
which produce another macro or macro text file.
as we know
text type %T1%
will display the result of %T1%
ex>a,b,c,...etc...
but I want to display %T1% itself
ex> %T1%
please let me know how to do it...