var/Level1=copytext(num2text(Y.Level),1,2)//This'll output something like 5.
var/Level2=copytext(num2text(Y.Level),2)
var/LV=file("[Level1].png")//Refer to 5.png
var/LV2=file("[Level2].png")
winset(src,"Map.Level1","image=['[LV]']")//Set 5.png as the image file on label.
winset(src,"Map.Level2","image=['[LV2]']")
Problem description:
Unable to set variables inside square brackets, and I'm not sure how else to approach the situation.
The above works fine, so as long as your file finding system works, then this should.