Definatly. All you need is a stero Jack plug to phono leads. (this has a "headphone plug" on one end and "phone plugs" the other, the phone plugs are the sockets on the end of the cables used to connect your 1210's to the mxer and the mixer to the amp. so you should be able to work out what the cable should look like.
Budget ones are availble in maplins for about £3.50 each. if you get two you can use your computer like a tape deck. connect the speaker out to tape 2 in and tape 2 record out too your line in. then Hey presto.;
You may have to set the record source in windows mixer as the line in. but your away.