Hello,
you can try to do it in Excel before loading data into SQL Server.
For instance, copy this text and create a new csv file:
a;1234.5;bbbbb
aa;"1,234.5";bbbb
aaa;1234.5;bbb
aaaa;1234.5;bb
aaaaa;1234.5;b
When you open this new file with Excel, the cell B2 has format "Number". If you the second column to format "General" and save the file, all data in the second column will take the same appearance.
Francesc