Different formats in Excel column into 1 format to load into table

Question

I have a situation in hand. I have to do a SQL Load into a Temporary table from an Excel file but I noticed that the column I am most interested in has about 4 different formats. My desired format will always have to be 7 characters long and has to only have digits in them. That means, no hyphens or special characters or alphabets.
I have found out that the column in Excel has pretty much 4 or 5 different formats:
Here is what they are supposed to be transformed into :
42 = 0000042
000-0257 = 0000257
0090647 = 0090647 (Corect Format)
709782 = 0709782
135566F1 = 0135566
The last case only seems to have 2 or 3 lines where this Alphabet comes in but then anything after that needs to be discarded. I could probably just remove them ( The F1 ) from the File manually.
Any ideas ? Thanks in advance.

Answer 1

Thanks Frank, for showing a far better way to translate the chars 'away'.
However, the last record contains the 1 that comes after the F?
I've pasted your example into my 'beta-clunged'-version (I know it can become far more compact, but wanted to show the steps taken):
SQL> with t as (
  2  select '42' col from dual union all
  3  select '000-0257' from dual union all
  4  select '0090647' from dual union all
  5  select '709782' from dual  union all
  6  select '135566F1' from dual
  7  )
  8  select col
  9  ,      to_char( replace( col2
10                         , '-'
11                         )
12                , 'fm0000000'  -- 3. apply the format mask
13                ) my_clunging
14  ,      lpad ( translate ( col
15                          , '0123456789' || translate ( col
16                                                      , 'x0123456789'
17                                                      , 'x'
18                                                      )
19                          , '0123456789'
20                          )
21              , 7
22              , '0'
23              ) franks_solution
24  from  ( select col
25         ,       case when instr( translate( lower(col)
26                                           , 'abcdefghijklmnopqrstuvwxyz'
27                                           , 'xxxxxxxxxxxxxxxxxxxxxxxxxx'
28                                           )
29                                , 'x'
30                                ) > 0
31                      then -- 1. eliminate string after finding a character
32                           substr( col
33                                 , 1
34                                 , instr( translate( lower(col)
35                                                   , 'abcdefghijklmnopqrstuvwxyz'
36                                                   , 'xxxxxxxxxxxxxxxxxxxxxxxxxx'
37                                                   )
38                                        , 'x'
39                                        ) -1
40                                 )
41                     else col
42                 end col2
43          from t
44        );
COL      MY_CLUNG FRANKS_
42       0000042  0000042
000-0257 0000257  0000257
0090647  0090647  0090647
709782   0709782  0709782
135566F1 0135566  1355661Didn't you notice that in your tests, Raj, or have your requirements changed?