Hi mikrom,
First of all, thanks for your reply.
You are right, I mean add Y coordinates instead of Z coordinates!
You understood correctly, I only made a mistake in the end, I want to end up with:
expr[1 + $var1] expr[$var2] expr[10 + $var3]
expr[2 + $var1] expr[$var2] expr[20 + $var3]
...