ASP.Net: Format String for Numeric Value in German Culture using C#

Hello there,

I have this string 307434,03 on my aspx page using C#

I need this output 307.434

I have tried using 

Text='<%# String.Format("{0:N0}", Eval("DC_CA").ToString())

But the return not changed it's 307434,03

The column DC_CA of the table MySQL it's set varchar 255

The column DC_CA of the table MySQL, contains a decimal number, 307434,03

In gridview I need to format 307434,03 string as integer.

In "de"(German) the number should be in 307.434

Thanks in advance for any help