User Name DB LOOKUP HELP.

Hello, 

hopping somebody can help, not sure if this has been spoke about before on here or not. 

please point me into the direction if it has. 

I'm looking at creating a user log on and password section.

Example - 

User Inputs User Code and password.  - the User code is then put into a VLOOKUP in the DB to find the associated password. if correct displays said users data. 

has anybody done/seen this before. I've generated it via Ladder but its very long winded and if it comes to having multi users (+50 its a lot of copy and paste). 

Thanks in advance. 

Dan