CUI Macro?

[aesoton]

This follows on from an earlier thread (Centre of Polyline and scale) but I thought that it is different enough to warrant a new thread. I am using AutoCAD LT at the moment and cant find the tool for running lisps. Is this possibly because AutoCAD LT can't do this? So I have had a go at creating a command in the CUI although I have very little idea of what I am doing.
The basic command that I want to fuse together are.
1) create region from polyline
^C^C_region
2) Read the mass properties using massprop
^C^C_massprop
3) read the centroid x and y values from massprop and use them to scale by.
4) scale by a factor of 0.9
$M=$(if,$(eq,$(substr,$(getvar,cmdnames),1,4),GRIP),_scale,^C^C_scale)

Is there any way to combine these commands into one?

 

[aesoton]

So far I have managed to work out th following

This creates a region from a polyline and then calls up the mass properties.

^C^Cregion;\;_^C^C_massprop^M\;N;

but how to ask it for the x and y centroids?

Andrew299