Smart Forms - Set decimal places in display formatting

Hello,

i have a variable (quantity 15 field with 3 decimal places) which i want to print via smartforms.

sap help describes that you have to set (.<number>)

for example: &field(.2)& to do that.

this doesn t work at all.

Does anybody know how you can do that?

I would appreciate an answer, because that costs me already alot of time.

thanks alot!

Jasmin