Assuming you're actually setting bit 1 in CONTROL, this will work;

IF CONTROL.0[X] THEN ' IF CONTROL.BIT.X = 1 THEN do something.

X is the bit index pointer 0 to 7. The .0 just tells PBP it's a bit.

If your variable is in bank 0, this works fine. If it's not, or you're just
not sure, then use CHK?RP in your assembler routine to look up the
bank for the var you're using.

ASM
CHK?RP _CONTROL
bsf _CONTROL,1
ENDASM

CHK?RP is a PBP macro that just looks up the variable register bank.