Problem with passphrase against desired pass

Hi all, We have a wrt120n router (Linksys-Cisco) connected to another router (cisco too) which doesn´t support any kind of encryption but only wep.
The problem starts when trying to set our wep security on the wrt120n , the device only gives us the option to generate a WEP from a passphrase, but we want the pass to be the passphrase itself, I mean, for example "School4" or "Office3" instead "DAG1234AB" (hex).Do you know any way to solve this setting a our desired password?

Thnx in advance 4 ur time, kind regards.