Any portion that uses that $server variable will more than likely not work.

What the Val() function does int he first line is tries to get the numerical value of the %logonserver%. It stops when it reaches the first non numeric character, and will simply return a 0 if non are encountered...so in the case of OFFDC01, the $server variable will become '0FNP01' instead of something like '7777FNP01'.

You could add an IF statement before the segment of the script that uses the $server variable to ensure it was set correctly first...For example...
 Code:
IF Len($servernumber)>1
   net use i: $server+"\sharename"
   net use j: $server+"\sharename"
   etc...
EndIf