Populating SQLite table with Tcl script in SQLiteStudio

I'm trying to populate two INTEGER fields of a table in SQLite Studio with Tcl script feature of SQLiteStudio. The table itself is a representation of a m✕n rectangular matrix, where those two fields represent elements' indices.

I've tried to recreate a surrogate for loop with the following script for the first field:

set i 0
set i [expr {$i==100?1:$i+1}]

and this script for the second one:

set j 0
set j [expr {$i==100?$j+1:$j}]

While the first script populates field i normally, the second one displays Error while executing populating code: can't read "i": no such variable error message, and the j field is populated with null values.

Is there any way to use SQLiteStudio's population mechanism this way (i.e. accessing field's new value from scope of another field's population Tcl script)?