Scale factor and scaled icon position in appfilter.xml

I'm a icons themer for Android and unfortunately I'm not very familiar with programming languages.

My problem is with a file. Xml "appfilter.xml."

Through this xml, in addition to declaring the drawable for the various "activities" that I designed, there is also the possibility to define a scale factor so that the icons that I have not drawn, are scaled and placed in a "iconback" (a basic icon with the theme of equal basis equal to the other), in order to give a more linear look.

What I need is I can not define, as well as the scale factor, although the exact location of where the original icon is put in my iconback. By default, only defining the scale factor, it is placed centrally, but I want it in a different location.

how could I do to get full control over the position of the icons do not draw from me in the "iconback"?

Thank you all for the help.