No macro - use Vlookup

Hi ALL,
I have two excels with following details where i am doing Vlookup from one excel into the other.

Now in case if the data in first excel is not found , i search for one character less from second excel.
not sure if its possible in excel.


Data is like.

Excel1.xls

ColA ColB
2011510629 A
201151062 D
2001510 F
200014 G
120012 Q

The excel where i want ot performa the Vlookup has data as such.


ColA ColB
2011510629 121
2011510622 2
20015103 4
200014 4
120012 4
in case of first values in ColA excat match can be found in previous excel. however for second one no exact match is there , in this case we need to seach it again using one charecter less and this will continue till be find a exact match.

Hope somebody will have to a way to crack this using excel.