Try this [edited]

HCL Notes/Domino 8.5 Forum (includes Notes Traveler)

Subject:

Try this [edited]

I once wrote a small LotusScript Function for this; see below. Hope it will work for you.
NO WARRANTIES (since this is for banks ;-)

<EDIT>
Ouch, 24 digits is more than the precision of a Double, so it won't work I'm afraid.
You'll probably have to resort to Java; see class BigInteger.
</EDIT>

'/**
' * Max Long value
' */
Public Const N_LS_MAXLONG& = 2147483647 ' &h7FFFFFFF

'/**
' * Performs a Modulo operation, where the left operand can be greater than <code>N_LS_MAXLONG</code>.
' * @param leftOp left operand
' * @param rightOp right operand
' * @return the value of <code>leftOp Mod rightOp</code>, if <code>Abs(leftOp) <= N_LS_MAXLONG</code>, otherwise the value of <code>leftOp - Fix(leftOp/rightOp) * rightOp</code>.
' * @error 11 (ErrDivisionByZero) if <code>rightOp</code> is zero.
' */
Public Function BigMod(ByVal leftOp As Double, ByVal rightOp As Long) As Long
If Abs(leftOp) <= N_LS_MAXLONG Then
BigMod = leftOp Mod rightOp
Else
BigMod = leftOp - Fix(leftOp/rightOp) * rightOp
End If
End Function

Feedback response number JSAK9G9PQW created by ~Tip Zekjumitexakol on 02/12/2014