What I'm trying to do is the following:

if cell(a1) is different from 0(zero) then, cell(b1) should have a comment
that say, the value of cell(c1) is the payment, next line the value of
cell(a1) was refund, next line Total for today = cell(c1)-cell(a1)

Example
a1 = $10.00
c1 = $30.00

B1 (comment):
$30.00 is the payment (c1)
$10.00 was refund (a1)

Total for today: $20.00 (c1-a1)

can anyone help me on that?

thanks in advance