two formula questions

[Legacy 177405]

i need a formula that will pull a number from sheet one in a workbook and display it in sheet two. the specific application is for account numbers however in sheet two i only want the result of the formula to return the last four digits of the account or xxx1234. to be clear the value would be displayed in sheet one as a full 7 digit # then sheet two would have a formula linking to sheet one... i want the the formula to return only the last four digits of the number string in sheet one.

secondly, i would like to link a value in sheet two to a value in sheet one, however if the primary cell is blank i would like the formula to pull from a second cell. is this possible. hopefully i have been clear enough... let me know if i can provide any more detail. thanks in advance for the help
richard keyser

 

[Peter_SSs]

Three choices

=RIGHT(Sheet1!A1,4)
will give 4567 but as a text value not a number

="xxx"&RIGHT(Sheet1!A1,4)
will give xxx4567 which is obviously a text value

=RIGHT(Sheet1!A1,4)+0
will 4567 as a number, not text.