The macro below will produce the powers in a maths equation by making the powers size 8 and raising them by 2 points. To do this, put a ‘z’ in front of anything you want to be a power. For anything that you want to be a subscript put a ‘q’ in front of it and it will be lowered by 2 points and made size 8. So to make the following equation:

first insert a fraction from Insert>Equation:

then type (pSOq3)z2 on the top line and (pSOq2)z2 (pOq2) on the bottom line. Then run the macro below. It will also change Cambria Math (sic) font to Arial and get rid of the italics.
Sub MathsEquationsRaisePowersWithZ()
Selection.Find.ClearFormatting
Selection.Find.Replacement.ClearFormatting
With Selection.Find.Replacement.Font
.Size = 8
.Superscript = False
.Subscript = False
.Position = 1
End With
With Selection.Find
.Text = "([z])([-])"
.Replacement.Text = "\2"
.Forward = True
.Wrap = wdFindContinue
.Format = True
.MatchCase = False
.MatchWholeWord = False
.MatchAllWordForms = False
.MatchSoundsLike = False
.MatchWildcards = True
End With
Selection.Find.Execute Replace:=wdReplaceAll
Selection.Find.ClearFormatting
Selection.Find.Replacement.ClearFormatting
With Selection.Find.Replacement.Font
.Size = 8
.Superscript = False
.Subscript = False
.Position = 2
End With
With Selection.Find
.Text = "([z])([0-9])"
.Replacement.Text = "\2"
.Forward = True
.Wrap = wdFindContinue
.Format = True
.MatchCase = False
.MatchWholeWord = False
.MatchAllWordForms = False
.MatchSoundsLike = False
.MatchWildcards = True
End With
Selection.Find.Execute Replace:=wdReplaceAll
Selection.Find.ClearFormatting
Selection.Find.Replacement.ClearFormatting
With Selection.Find.Replacement.Font
.Size = 8
.Superscript = False
.Subscript = False
.Position = -2
End With
With Selection.Find
.Text = "([q])([0-9])"
.Replacement.Text = "\2"
.Forward = True
.Wrap = wdFindContinue
.Format = True
.MatchCase = False
.MatchWholeWord = False
.MatchAllWordForms = False
.MatchSoundsLike = False
.MatchWildcards = True
End With
Selection.Find.Execute Replace:=wdReplaceAll
For Each equation In ActiveDocument.OMaths
equation.Range.Font.Italic = False
Next equation
'Selection.TypeText Text:=" "
For Each equation In ActiveDocument.OMaths
equation.Range.Font.Name = "Arial"
Next equation
End Sub