Go to your print office and see if they have 11x 7 size paper. If so find out what tray it is in (probably Tray # 3).
If your file is an Adobe Reader file (.pdf) then with the music score on the computer screen do the following:
1) Left click FILE 2) Left click PRINT SETUP 3) Left click PROPERTIES 4) Left click PAPER 5) Left click on the Size is: (black triangle) 6) Choose paper size 11x17 7) Left click OK

Under Auto Select left click on TRAY 3 9) Left click OK 10) Left click on tht Left top PRINT ICON 11) Left click OK and wait 30 seconds for the Adobe program to process your request.
Complicated ... but it may work
Theodore