print variable in file using awk

hi,

i have store variable in $var i want to print it in $3 of file using awk.
how can i do it?

file :

var1,var2,var3
var5,var6,var7
var8,var9,var10
.
.
.

i want to print $var in $3 ( for example var3 or var7 or var10)

thanks

awk -F',' -v avar=$var '{printf("%s,%s,%s\n",$1,$2,avar);}' file

$ cat file
var1,var2,var3
var5,var6,var7
var8,var9,var10
~

$ awk -F, '{print $3}' file
var3
var7
var10

$
is this what you wanted?

var=3
awk -F',' -v avar=$var '{print $avar}' file