Modify formula stored in string via VBA - regex

Question

(I have hundreds of rows need to change. The data is like this
activity_id equation
5225518 D0312_ABC * (S3765+S3790+S3762+S3763+S3770+S3764+S4480) * (1-(S2820+S0560))*(1-S1965)*(1-C0151)
7306234 D0300_BCD * C0502 * (1-(S0191))*(1-S1965)
8293425 D0798_CDE * P0692 * (1-(S0191+S2820+S0560+S0290+S0960))*(1-S1965)
9119429 D0793_DEF * S2605 * (1-S0290)*(1-S1965)
I need to combine the two "1-something" together and there is a pattern.
When ever there is a (1-(Sxxx+Sxxxx))*(1-(Sxxx+Sxxxx)),
combine them into one which is (1-(Sxxx+Sxxxx +Sxxx+Sxxxx))
So I only need to change everything with Sxxxx, you can ignore Cxxxx, Dxxxx, Pxxxx, ...
SO I need to change it to:
activity_id equation
5225518 D0312_ABC * (S3765+S3790+S3762+S3763+S3770+S3764+S4480) * (1-(S2820+S0560+S1965))*(1-C0151)
7306234 D0300_BCD * C0502 * (1-(S0191+S1965))
8293425 D0798_CDE * P0692 * (1-(S0191+S2820+S0560+S0290+S0960+S1965))
9119429 D0793_DEF * S2605 * (1-(S0290+S1965))

Answer 1

The following regexp certainly may and arguably should be improved.
Option Explicit
Private m_Rex As RegExp
Private Const SEARCH_PATTERN As String = "\(1-\(?((S\d{4}\+?)+)\)?\)\*\(1-\(?((S\d{4}\+?)+)\)?\)"
' $0 $2
Private Const REPLACE_PATTERN As String = "(1-($1+$3))"
Public Function Simplify(ByVal AVeryParticularFormula As String) As String
If m_Rex Is Nothing Then
Set m_Rex = New RegExp
m_Rex.Global = False
m_Rex.MultiLine = False
m_Rex.IgnoreCase = False
m_Rex.Pattern = SEARCH_PATTERN
End If
Do
Simplify = m_Rex.Replace(AVeryParticularFormula, REPLACE_PATTERN)
If Simplify = AVeryParticularFormula Then Exit Do
AVeryParticularFormula = Simplify
Loop
End Function
? Simplify("D0312_ABC * (S3765+S3790+S3762+S3763+S3770+S3764+S4480) * (1-(S2820+S0560))*(1-S1965)*(1-C0151)")
D0312_ABC * (S3765+S3790+S3762+S3763+S3770+S3764+S4480) * (1-(S2820+S0560+S1965))*(1-C0151)
? Simplify("D0300_BCD * C0502 * (1-(S0191))*(1-S1965)")
D0300_BCD * C0502 * (1-(S0191+S1965))
? Simplify("D0798_CDE * P0692 * (1-(S0191+S2820+S0560+S0290+S0960))*(1-S1965)")
D0798_CDE * P0692 * (1-(S0191+S2820+S0560+S0290+S0960+S1965))
? Simplify("D0793_DEF * S2605 * (1-S0290)*(1-S1965)")
D0793_DEF * S2605 * (1-(S0290+S1965))