Importing Partials Datas From 2 Tables In Another One

I am having a problem to get all datas into one table
I must get datas from 2 other tables
datas from the first table are columns
but datas of the second table are rows

I cannot change the structure of TableA because an other application is using it as it is

TableA
num | value | key
1 | a | 1400
2 | b | 1401
3 | c | 1402
4 | d | 1403
...|... | 1403

TableB
key | name | descr | value
400 | john | ok | 451

TableC (the table where I want to insert datas from Table1 and Table2)

val1 | val2 | val3 | val4 |name | descr | value
1 | 2 | 3 |4 | john | ok | 451


TableA has thousands of rows and different numbers
I must get 8 different datas from TableA

so I get an horrible Query !

SELECT

TableB.name, TableB.descr, TableB.value,
TableA_1.value AS val1,
TableA_2.value AS val2,
TableA_3.value AS val3,
TableA_4.value AS val4,
TableA_5.value AS val5,
TableA_6.value AS val6,
TableA_7.value AS val7,
TableA_8.value AS val8

FROM dbo.TableB INNER JOIN
dbo.TableA_1 ON TableB.key = TableA_1.key INNER JOIN
dbo.TableA_2 ON TableB.key = TableA_2.key INNER JOIN
dbo.TableA_3 ON TableB.key = TableA_3.key INNER JOIN
dbo.TableA_4 ON TableB.key = TableA_4.key INNER JOIN
dbo.TableA_5 ON TableB.key = TableA_5.key INNER JOIN
dbo.TableA_6 ON TableB.key = TableA_6.key INNER JOIN
dbo.TableA_7 ON TableB.key = TableA_7.key INNER JOIN
dbo.TableA_8 ON TableB.key = TableA_8.key

WHERE TableA_1.num = 145
AND TableA_2.num = 80
AND TableA_3.num = 3160
AND TableA_4.num = 41
AND TableA_5.num = 50
AND TableA_6.num = 51
AND TableA_7.num = 53
AND TableA_8.num = 56


how can i do it in the best way ?

Thank you