Possible to change format of decimal fields?

Is it possible to change the format of a decimal field on mysql level?

We would like to use an open source solution though all the currency fields have to change. Values like: 1,2567.34 should be in european format: 1.2567,34. To change the source we have to change all the properties of the num_format($value,2) into num_format($value,2,'.',',') or ofcource better num_format($value,$Dec,$DecSep,$ThousSep).

Besides this changes a lot ot POST commands should be transformed as well, so, a lot of work could be solved when we can manage this on the mysql table.

How could we realize this? I see a field Transformation in the properties of a field. Could we do this there?

Anyway any help appreciated,

Perry