>FUNCTION NUMINSTR(STRING)
>
>FOR I = 1 To LEN(STRING)
> IF SUBSTR(STRING,I,1) $ "0123456789"
> RETURN .T.
> ENDIF
>NEXT

OR

FUNCTION NumInStr
LPARAMETERS tcString
* Perhaps speed things up a bit
tcString = ALLTRIM(tcString)
llRet = .F.
FOR lnCnt = 1 To LEN(tcString)
  IF ISDIGIT(SUBSTR(tcString,lnCnt,1))
    llRet = .T.
    EXIT
  ENDIF
ENDFOR
RETURN llRet