No variables, Xtreme is a vector drawing application.

Simply draw a line. For example a 200 pixel vertical line

Decide how much spacing you want, say 2 pixels.

Set the duplication distance in Options to 2 pixels for x and 0 or y. That is x and y as in graph paper coordinates.

Use Ctrl+Alt+D keys to duplicate the line as many times as you want.

Once you have the lines select them all and group.

Use Ctrl+K keys to clone the group.

Enable the rotation handles on the clone group and drag a corner rotation handle and move the clone so it give the moire effect you want.

Sounds complicated but can be done in less than 10 seconds.