okay well I went to grab the code linked by M. I. Wright, and it works, but I would need it to be able to handle decimals and negative numbers, for now, it outputs the number and stores it to C, but will return a syntax error if the negative or decimal keys are pressed...
Code: DelVar CDelVar B
1->A
Lbl A
Repeat Ans>71 and min(Ans!={45,75,81,85
getKey
End
sub("789 456 123 0.~",Ans-36-5int(.1Ans),1
expr(Ans->B
Output(1,A,Ans
If A=1:Then
B->C:A+1->A:Goto A
Else
10C+B->C
A+1->A
Goto A
edit:I worked on it a little today and managed to get the negative numbers and decimal numbers working in pure basic, but I used the position of the text as a variable in the code, which worries me for implementation into the actual hybrid program where instead of having a 26*10 screen, i would have the half res mode screen, but here is the code I came up with, surely there is room for optimisation 
Code: DelVar CDelVar BDelVar F
1->A:1->D
Lbl A
Repeat Ans>71 and min(Ans!={45,75,81,85,91,95
getKey
End
If Ans=103:Then:C->E:DelVar C:2->F:A->G:Output(1,A,".":A+1->A:Goto A
Else:If Ans=105:Then:Goto B
Else:If Ans=104:Then:~1->D:A+1->A:Output(1,1,"~":Goto A
Else:If Ans!=104 and Ans!=105 and Ans!=103:Then
sub("789 456 123 0",Ans-36-5int(.1Ans),1
expr(Ans->B
Output(1,A,B
If not(A:Then
B->C:A+1->A:Goto A
Else
10C+B->C
A+1->A
Goto A
Lbl B
If F=2:Then:C/10^(A-G-1)->C
C+E->C
DC->C
Output(2,1,C
Pause
Else:If F!=2:Then:DC->C
Output(2,1,C
edit 2: worked on it some more, this time, got it into xLIBc, only thing is, can't have numbers over 9999, but thats always the case with xLIBc, and besides, noone needs big numbers like that lol anyways, it's nearing completion, will soon be putting it into the real program :3
Code: 1->I
"V1=V2= a= t= S=->Str2
Lbl C
10->H
real(0,1,1
real(0,3,4,8
sub(Str2,I,3->Str3
Str3
real(6,0,5,5,248
real(7,7,2,2,156,116,248
real(7,7,0,0,160,120,248,1
DelVar CDelVar BDelVar FDelVar J
1->A:1->D
Lbl A
Repeat Ans=45 or Ans>71 and min(Ans!={75,81,85,91,95
getKey
End
If Ans=103:Then:C->E:DelVar C:2->F:A->G:AH->H:2->J
A+1->A:Goto A
Else:If Ans=105:Then:Goto B
Else:If Ans=104:Then:~1->D
Goto A
Else:If Ans=45:Then:Goto C
Else:If Ans!=104 and Ans!=105 and Ans!=103:Then
sub("789 456 123 0",Ans-36-5int(.1Ans),1
expr(Ans->B
If not(A:Then
B->C:A+1->A:Goto A
Else
10C+B->C
A+1->A
real(0,3,4,8
real(7,7,2,2,156,116,248
real(7,7,0,0,160,120,248
Str3
real(6,0,5,5,248
If E and J=2:Then
",
real(6,0,H-6,15,248,0
End
If D=~1:Then
"-
real(6,0,3,15,248
End
If F=2:Then
real(6,1,10,15,248,E,0
End
real(6,1,H,15,248,C,1
Goto A
Lbl B
If F=2:Then:C/10^(A-G-1)->C
C+E->C
DC->C
Goto D
Else:If F!=2:Then:DC->C
Lbl D
I+3->I
Goto C
