several simple label expressions into a single expression

Could you help with combining several simple label expressions into a single expression?

I've made stabs at it but here it is with comments.

Lables are determined by three fields: [NAME], [DESCRIPTION], [NUMBER]

##If buildings have the following numbers, use muli-line labels to show Number and Name:
'332', '333', '334', '335', '336', '338', '339', '340', '343', '344', '345', '347', '362', '618', '1000', '1069', '1222', '1301', '1337', '1417', '2710', '3700', '3704', '3991', '4706', '5000', '5266', '5620', '6026', '6117', '6512', '6515', '6519', '6812', '7700', '7738', '8000', '8700', 'E47'
FindLabel = [NUMBER] newline [NAME]

##The following features do not have Numbers. They should NOT be labeled. Could these be filtered out with appropriate definition query?:
If ([NAME] = 'HN' + [DESCRIPTION] Is Null)

##These features do not have Numbers. They Should be labeled:
If ([NAME] = HN + [DESCRIPTION] = 'Not Null') FindLabel = [DESCRIPTION]

##buildings without numbers should be labeled by building name.
If IsNull ( [NUMBER] ) Then
FindLabel = [Name]

##Buildings with Numbers should be labeled by Number
[NUMBER]