Random numbers in a batch file

Hey this is my first program but i dont know how to set the random number right i want to get a number betwen 1 and 100

set /a number=%random% %%100 +1
:start
set number=%random%
if %v1% EQU %number% color 0a&&echo&&goto end
if %v1% LSS %number% &&goto start
if %v1% GTR %number% &&goto start
:end