How to detect float format by passing SQL_CHAR to float column ?

Hi,

as the documentation of postgresql, there is a floating point format
like 10.1234 but I do not see
10,1234. Is that ever like the documentation ?

The issue is because I pass a SQL_CHAR value from a GUI text control
that allows also a comma
in the string.

If there are commas possible, how do I detect it ?

Thanks, Lothar