If you're asking about using the Edit/Find menu function, choosing
Formulas in the Find dialog's Look In dropdown will look at formulas and
values.
If you're asking about a worksheet function, here's one way using a UDF:
Public Function FormulaFind( _
sText As String, _
rRange As Range) As Variant
If rRange.Count = 1 Then
If rRange.HasFormula Then _
FormulaFind = InStr(rRange.Formula, sText)
Else
FormulaFind = CVErr(xlErrValue)
End If
End Function
Call as
=FormulaFind("7",A1)
The function returns 0 if sText isn't found, or the cell doesn't contain
a formula. If for some reason you want to mimic XL's FIND function, use
Public Function FormulaFind( _
sText As String, _
rRange As Range) As Variant
Dim bValid As Boolean
If rRange.HasFormula Then
FormulaFind = InStr(rRange.Formula, sText)
bValid = FormulaFind > 0
End If
If Not bValid Then FormulaFind = CVErr(xlErrValue)
End Function
If you're unfamiliar with UDFs, see David McRitchie's "Getting Started
with Macros and User Defined Functions":
http://www.mvps.org/dmcritchie/excel/getstarted.htm