I have a puzzle that I need to know if it can be done...

I have a worksheet that I need data completed on and it contains these
columns.
Column 1 contains usernames that I provide in the document. The second
column contains a field the users that i give access to can input their
password in that they current use to access an application.

1 Username Password
2 name1 p.assword
3 name2
4 name3


I need users to complete this sheet filling in their password in column 2.
After the cell is complete and they press enter, i would like the cell to
***** out the entry and lock it so it can't be viewed/changed by anyone
except the document creator (me).

When the next viewer opens it, they will see this
1 Username Password
2 name1 *******
3 name2
4 name3

When the document owner opens the owner sees the password reveled...
1 Username Password
2 name1 p.assword
3 name2
4 name3

Note as an option the field could be password protected so the owner of the
document could type to reveal the hidden password...

Is there a way to do this in excell... without doing much programming.....