Why don't you encapsulate the code in the button above into a method:
int GetIntFromByteArr(byte[] rawLicense)
{
int i = rawLicense[3] + (rawLicense[2] << 8) + (rawLicense[1] << 16) + (rawLicense[0] << 24);
return j;
}
And call it multiple times?
int el1 = GetIntFromByteArr(new byte[]{0x00, 0x00, 0xA3, 0xE1});
int el2 = GetIntFromByteArr(new byte[]{0x00, 0x10, 0x00, 0xB1});
Then you would just concatenate those integers.
You could of course optimize this in such a way that you are passing the array to the method and the indexes that represent the start/end position to convert.
Hope this helps,
Alex