### Formula numbering - format

I just found out about the great way to enter a numbered formula - entering "fn" and pressing F3. However - is there a way to format the way these formulas are entered? I need to do two things:

- I need to number the formula using <chapter no.>.<formula="" no.>="" format,="" i.e.="" (3.5)<="" li="">
- the formula is centered horizontally - but I need it to be 2 centimeters from the left edge

How do I achieve this? Preferably for every formula in the document at once, but if not, I can also do it manually ...