I think you'll need a length verification.

Otherwise, your formula would accept this:

126PQR151008

Such as:

=AND(LEN(A1)=10,ISNUMBER(--LEFT(A1,3)),ISNUMBER(--RIGHT(A1,6)),ISERR(--MID(A
1,4,1)))
--
Regards,

RD

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"Gary''s Student" wrote in message
...
=AND(NOT(ISERROR(LEFT(A1,3)+RIGHT(A1,6))), ISERROR(MID(A1,4,1)+0))

the trick is that we can test if a set of characters is a number by adding
zero to it and see if we get and error.
--
Gary''s Student - gsnu200854


"aditya" wrote:

how can i write formula for custom validation for a cell like this.

first 3 digit shoulg be a number, next digit should be a text then next
6
digit should be number.

e.g. 126P151008

thanks in advance