well i didnt understand u actually......i did an IR related project......
tell me .......remote control unit sends signal to ur PC? and then according to signal
u wanna flash specific IR leds, which trigger energy?
is it ur problem? let me know.......i will answer this...
well may b i understood the last part of ur question........ya u can easily sharpen the IR frequency to sufficient enough to ur purpose......
u can use TIMER 555 (NE 555) ic.....which generates ur require frequency (10-90kHz)
with this.......by changing value of capacitor and resistance in the timer circuit , will change the freq at output trigger.
i will write in details, pin diagram, frequ calculation formula if u want.