It is regularly done for RSI. In fact I have discussed the same in my Pune Chapter Meeting, video archives to this should be loaded shortly. Refer to it and you will get the information about RSI Bands, that are generated using different period RSI.

yes you can there is a syntax in afl coding

this is a good place to start learning on the multiple time frame support on amibroker
www.amibroker.com/guide/h_timeframe.html

personally i have used it on intraday and this is the code
Plot(C,"",3,64);
TimeFrameSet(in5Minute);
A3= StochD( 14, 3, 3 ) > Ref( StochD( 14, 3, 3 ) , -1 );
TimeFrameRestore();
k5b = TimeFrameExpand(A3, in5Minute);
Cond11= k5b == 1;

TimeFrameSet(2*in15Minute);
A3= StochD( 14, 3, 3 ) > Ref( StochD( 14, 3, 3 ) , -1 );
TimeFrameRestore();
k30b = TimeFrameExpand(A3, 2*in15Minute);
Cond5= k30b == 1;

TimeFrameSet(in15Minute);
A1= StochD( 14, 3, 3 ) > Ref( StochD( 14, 3, 3 ) , -1 );
A2= StochD( 14, 3, 3 ) > 98 ;
A3= TimeNum() > 152000;
TimeFrameRestore();
k15b = TimeFrameExpand(A1, in15Minute);
k15s = TimeFrameExpand(A2, in15Minute);
k15t = TimeFrameExpand(A3, in15Minute);