how to insert line break in a formula

[earlyadopter]

What is the way to write a formula which will produce the same result as entering Alt-Enter manually, i.e. if I need content of two concatenated fields to be on different lines inside the combined cell?

Example:

cell A1="string_1"
cell B1="string_2"

And I need cell C1 to be:
cell C1=
"string_1
string_2"

I tried c1="concatenate(a1, CHAR(10),b1)"
it doesn't work -- shows a little square between the values of a1 and b1 instead of makeing a line break.

Would appreciate ideas.

 

[earlyadopter]

I found an answer myself.
It's necessary to have wrap text in a cell enabled - then CHAR(10) works as expected!