Excel macro and "months"

Hi!
I'm new to macro coding and need some help.

I have an excel sheet that has cell B3 filled with a month (i.e. December). I also have an existing macro for that sheet that, when ran, will move data from one column to another column then clearing the original column. I would also like to have the same macro recognize the month already resident in cell B3, and increment that content to the next month when the macro is ran.
In other words, cell B3 contains the month "December". When I run the macro, it reads cell B3, then increments the month such that cell B3 will now read the month "January".

Here is the macro code I have currently:

Sub UPDATE()
'
' UPDATE Macro
' Macro created by 373 TRS
'
'
Sheets("43 MXS").Select
Range("D4:F41").Select
Selection.Copy
ActiveWindow.LargeScroll Down:=-3
Range("C4").Select
ActiveSheet.PasteSpecial Format:=7, Link:=1, DisplayAsIcon:=False, _
IconFileName:=False
Range("F4").Select
ActiveCell.FormulaR1C1 = "0"
Range("F4:F41").Select
Selection.ClearContents
Range("F4").Select
Sheets("2 AS").Select
Range("D4:F41").Select
Selection.Copy
ActiveWindow.LargeScroll Down:=-3
Range("C4").Select
ActiveSheet.PasteSpecial Format:=7, Link:=1, DisplayAsIcon:=False, _
IconFileName:=False
Range("F4").Select
ActiveCell.FormulaR1C1 = "0"
Range("F4:F41").Select
Selection.ClearContents
Range("F4").Select
Sheets("41 AS").Select
Range("D4:F41").Select
Selection.Copy
ActiveWindow.LargeScroll Down:=-3
Range("C4").Select
ActiveSheet.PasteSpecial Format:=7, Link:=1, DisplayAsIcon:=False, _
IconFileName:=False
Range("F4").Select
ActiveCell.FormulaR1C1 = "0"
Range("F4:F41").Select
Selection.ClearContents
Range("F4").Select
Sheets("743 MXS").Select
Range("D4:F41").Select
Selection.Copy
ActiveWindow.LargeScroll Down:=-3
Range("C4").Select
ActiveSheet.PasteSpecial Format:=7, Link:=1, DisplayAsIcon:=False, _
IconFileName:=False
Range("F4").Select
ActiveCell.FormulaR1C1 = "0"
Range("F4:F41").Select
Selection.ClearContents
Range("F4").Select
Sheets("TDY").Select
Range("D4:F41").Select
Selection.Copy
ActiveWindow.LargeScroll Down:=-3
Range("C4").Select
ActiveSheet.PasteSpecial Format:=7, Link:=1, DisplayAsIcon:=False, _
IconFileName:=False
Range("F4").Select
ActiveCell.FormulaR1C1 = "0"
Range("F4:F41").Select
Selection.ClearContents
Range("F4").Select
Sheets("898").Select
Range("J9:J236").Select
Application.CutCopyMode = False
Selection.Copy
ActiveWindow.LargeScroll Down:=-3
Range("I9:I236").Select
Selection.PasteSpecial Paste:=7, Operation:=xlNone, SkipBlanks:=False, _
Transpose:=False
Application.CutCopyMode = False
With Selection
.HorizontalAlignment = xlLeft
.VerticalAlignment = xlTop
.WrapText = False
.Orientation = 0
.IndentLevel = 0
.ShrinkToFit = False
End With
Range("L9:L236").Select
Selection.Copy
ActiveWindow.LargeScroll Down:=-3
Range("J9:J236").Select
Selection.PasteSpecial Paste:=7, Operation:=xlNone, SkipBlanks:=False, _
Transpose:=False
Range("L9:L236").Select
Application.CutCopyMode = False
Selection.ClearContents
Range("N9:N236").Select
Selection.Copy
ActiveWindow.LargeScroll Down:=-3
Range("M9:M236").Select
Selection.PasteSpecial Paste:=7, Operation:=xlNone, SkipBlanks:=False, _
Transpose:=False
Range("O9:O236").Select
Application.CutCopyMode = False
Selection.Copy
ActiveWindow.LargeScroll Down:=-3
Range("N9:N236").Select
Selection.PasteSpecial Paste:=7, Operation:=xlNone, SkipBlanks:=False, _
Transpose:=False
Range("O9:O236").Select
Application.CutCopyMode = False
Selection.ClearContents
Range("P9:Q13").Select
End Sub

Any help will be greatly appreciated.

Thanks

A10 Instructor