Numeric inputs

[hation-hation]

Hello guys

I am curious if is it possible to scale faces of the object numerically?
For example:
I have a model of chair and want to scale every leg(the leg is part of the object and I select only the faces of every leg) the exact same amount in two direction x,y.

I get a solution from member of another forum.

Create a cluster for the components on each leg, and then you can scale the clusters with all the same values.

Now my question is will it be a difficult to make a script/plugin that do a little window for input a x,y,z in every manipulation ?