[Arrays] Handling NA's in REST 2008 software

[Testing]

Hello, 
 
Can any PCR data analysis experts in the forum please answer this question ?
 
How does one handle NA's (unknown data items) while analysing PCR data
using REST 2008 software ? 
 
NA are not accepted by the program. While zeros are accepted, I suspect, the results are not correct if zeros are used instead of NAs.
 
Thanks
Suki