Change value at specific address in assembly

I'm writing assembly in LC-3. I have a register, R1, that points to a specific address. How do I change the value at that address to 0? Unfortunately, this is due really soon, so prompt help would be greatly appreciated! Thanks!

PS: If you don't know LC-3, here are the 15 instructions: ADD,开发者_StackOverflow中文版 AND, BR, JMP, JSR, JSRR, LD, LDI, LDR, LEA, NOT, RET, RTI, ST, STI, STR, TRAP

You'd start by zeroing another register (e.g., R0). Since there's no instruction to clear a register, one obvious choice would to AND that register with an immediate value of 0 (another would be to subtract the register from itself). Likewise, the instruction set doesn't have a simple "store indirect", but it does have a "store indirect with offset" (STR), so your source register would be the one you cleared, the destination register would be R1, and the offset would be 0 (#0).