You can, if you define the number stored within the N7 address to be 10^n x the actual variable.
For example, If I want a setpoint of 56.7 degrees, and I wanted to store it in N7:1 I could enter 567 in that address. However, keep in mind that your program would have to be aware of the situation and use the variable in that form (ie degrees x 10 in the SP as well as PV for a PID block).
If you needed to access the number as degrees once again, you could do a number of things to display that number (ie. configure the HMI to add a decimal position, or just divide the number by 10).