Data Validation for Letters and Numbers

[cowsbark]

I am attempting to restrict a cell in an excel form to letters and numbers in the following format: ##XXX #### ####.

The spaces are not crucial (though would be beneficial). This seems like it should be simple enough, but I cannot figure it out. Thank you.

[cowsbark]

I tried the following formula:

=AND(LEN(A1)=13,ISNUMBER(LEFT(A1,2)),ISTEXT(MID(A1,3,3)),ISNUMBER(RIGHT(A1,8)))

But it is not working for some reason.

[FDibbins]

Perhaps it would help is you gave a few sample of your data?

[cowsbark]

Sure. The "Data to input" cell shows an example of a string of characters to which I want to restrict input, while the "Example Cell" has the Data Validation restriction applied.